Mortality, bone density and grip strength: lessons from the past and hope for the future?

Objectives: Therapeutic advances in the management of osteoporosis and sarcopenia have occurred at different rates over the last 2 decades. Here we examine associations between grip strength and BMD with subsequent all-cause and cause-specific mortality in a UK community-dwelling cohort. Methods: Data from 495 men and 414 women from the Hertfordshire Cohort Study were analysed. Grip strength was assessed by grip dynamometry, femoral neck BMD was ascertained using DXA and deaths were recorded from baseline (1998-2004) until 31 December 2018. Grip strength and BMD in relation to mortality outcomes (all-cause, cardiovascular-related, cancer-related and mortality due to other causes) were examined using Cox regression with adjustment for age and sex. Results: The mean baseline age of participants was 64.3 years (s.d. 2.5) and 65.9 years (s.d. 2.6) in men and women, respectively. Lower grip strength was associated with increased risk of all-cause mortality [hazard ratio (HR) 1.30 (95% CI 1.06, 1.58), P = 0.010] and cardiovascular-related mortality [HR 1.75 (95% CI 1.20, 2.55), P = 0.004]. In contrast, BMD was not associated with any of the mortality outcomes (P > 0.1 for all associations). Conclusion: We report strong relationships between grip strength and mortality compared with BMD. We hypothesize that this may reflect better recognition and treatment of low BMD in this cohort.

Could self-reported physical performance help predict individuals at the highest risk of mortality and hospital admission events in clinical practice? Findings from the Hertfordshire Cohort Study.

AIM: To consider how self-reported physical function measures relate to adverse clinical outcomes measured over 20 years of follow-up in a community-dwelling cohort (aged 59-73 at baseline) as compared with hand grip strength, a well-validated predictor of adverse events. BACKGROUND: Recent evidence has emphasized the significant association of physical activity, physical performance, and muscle strength with hospital admissions in older people. However, physical performance tests require staff availability, training, specialized equipment, and space to perform them, often not feasible or realistic in the context of a busy clinical setting. METHODS: In total, 2997 men and women were analyzed. Baseline predictors were measured grip strength (Jamar dynamometer) and the following self-reported measures: physical activity (Dallosso questionnaire); physical function score (SF-36 Health Survey); and walking speed. Participants were followed up from baseline (1998-2004) until December 2018 using UK Hospital Episode Statistics and mortality data, which report clinical outcomes using ICD-10 coding. Predictors in relation to the risk of mortality and hospital admission events were examined using Cox regression with and without adjustment for sociodemographic and lifestyle characteristics. FINDINGS: The mean age at baseline was 65.7 and 66.6 years among men and women, respectively. Over follow-up, 36% of men and 26% of women died, while 93% of men and 92% of women were admitted to hospital at least once. Physical activity, grip strength, SF-36 physical function, and walking speed were all strongly associated with adverse health outcomes in both sex- and fully adjusted analyses; poorer values for each of the predictors were related to greater risk of mortality (all-cause, cardiovascular-related) and any, neurological, cardiovascular, respiratory, any fracture, and falls admissions. SF-36 physical function and grip strength were similarly associated with the adverse health outcomes considered.

Lifecourse correlates of self-rated health and associations with subsequent mortality: findings from the Hertfordshire Cohort Study.

Background: Poor self-rated health (SRH) has been shown to predict adverse health outcomes among older people, however these associations have traditionally only been considered at one point in the lifecourse, usually midlife or later. Here we examined lifecourse correlates of SRH in early, mid and later life, relating these to subsequent risk of mortality in a community-dwelling cohort. Methods: 2989 men and women from the Hertfordshire Cohort Study (HCS) were included in this study. The HCS was initially retrospective and linked contemporary health outcome data to early life data available from health ledgers but investigations from baseline (1998-2004, aged 59-73) onwards have been prospective. At baseline, participants completed an initial clinic visit, which included questionnaire assessment of SRH, reported as 'excellent', 'very good', 'good', 'fair', or 'poor'. Socioeconomic, lifestyle, mental health and demographic information was also collected. Deaths were recorded from baseline to 31/12/2018. Baseline characteristics in relation to SRH were examined using sex-stratified ordinal logistic regression; these factors were examined in relation to mortality using sex-stratified Cox regression. Statistically significant exposures were then included in sex-stratified mutually-adjusted models. Results: In mutually-adjusted analysis, numerous contemporaneous correlates of poorer SRH in the seventh decade were identified and included obesity, lower physical activity, greater comorbidity and higher levels of depression among men and women. For example, odds ratios for being in a lower category of SRH were as follows: obese (BMI≥30) vs underweight/healthy (BMI<25) (men 1.60 (1.21, 2.11), women 1.65 (1.25, 2.17)) and per additional system medicated (men 1.62 (1.47, 1.77), women 1.53 (1.41, 1.66)). By contrast, factors earlier in the lifecourse (early growth, age left full-time education) were not associated with SRH in late adulthood. 36% of men and 26% of women died during follow-up. Hazard ratios (95% CI) for mortality per lower category of SRH were 1.22 (1.10,1.36) among men and 1.17 (1.01,1.35) among women after adjustment for age, BMI, smoking, physical activity, diet quality, education, home ownership status, comorbidity level and depression levels, suggesting residual confounding by other unrecorded factors that are related to SRH. Conclusions: Poorer SRH in the seventh decade was a risk factor for mortality. Importantly modifiable adverse health behaviours in the seventh decade, such as low physical activity, were associated with poorer SRH and later mortality after adjustment for socioeconomic factors and comorbidity level. By contrast early growth and education were not related to later SRH. These data suggest that attention to lifestyle in late midlife may be associated with better SRH and subsequent health outcomes, highlighting the value of intervention at this stage of the lifecourse.

Fracture Risk and Health Profiles Differ According to Relationship Status: Findings from the Hertfordshire Cohort Study.

Registry studies have suggested associations between relationship status and fracture risk. We considered associations between relationship status and incident fracture in the Hertfordshire Cohort Study, comprising community-dwelling older adults, and explored associations between socioeconomic and lifestyle factors with relationship status. 2997 participants completed a baseline questionnaire (1998-2004) and clinic visit. Participants were followed up until December 2018 using Hospital Episode Statistics, which report clinical outcomes using codes from the 10th revision of the International Classification of Diseases (ICD-10); these codes were used to ascertain incident fractures. Relationship status (not currently married/cohabiting vs currently married/cohabiting) at baseline was examined in relation to incident fracture using Cox regression. Associations between baseline characteristics and relationship status were examined using logistic regression. Mean baseline age was 66.2 years. 80% were married/cohabiting at baseline; 15% had an incident fracture (mean (SD) follow-up duration: 14.4 (4.5) years). The following were related to greater likelihood of not being married/cohabiting: older age (women only); higher BMI (women only); current smoking; high alcohol consumption (men only); poorer diet quality (men only); lower physical activity; leaving school before age 15 (women only); and not owning one's home. Those not married/cohabiting had greater risk of incident fracture compared to those who were (age-adjusted hazard ratios (95% CI) 1.58 (1.06, 2.38) among men, 1.35 (1.06, 1.72) among women); associations were attenuated after accounting for the above factors associated with relationship status in the corresponding sex. This suggests that differences in health profiles and lifestyle according to relationship status may explain the association between relationship status and fracture risk.

General self-efficacy, not musculoskeletal health, was associated with social isolation and loneliness in older adults during the COVID-19 pandemic: findings from the Hertfordshire Cohort Study.

BACKGROUND: Social isolation and loneliness are prevalent among older adults. This study investigated factors influencing worsening social isolation and loneliness in community-dwelling older adults during the COVID-19 pandemic, focusing on musculoskeletal conditions, falls, and fractures. METHODS: We studied 153 participants from the Hertfordshire Cohort Study. Baseline assessments (2019-20) included osteoporosis, clinical osteoarthritis, fractures after age 45 years, falls in previous year, and lifestyle factors. Self-efficacy was assessed using a shortened General Self-Efficacy Scale. Social isolation was assessed using the 6-item Lubben Social Network Scale. Follow-up (2020-21) assessments included social isolation and loneliness using the 6-item De Jong-Gierveld scale for emotional, social, and overall loneliness. RESULTS: Baseline median age was 83.1 years. A history of smoking predicted worsening social isolation (p = 0.046). Being married (p = 0.026) and higher self-efficacy scores (p = 0.03) predicted reduced social isolation at follow-up. Greater alcohol consumption was associated with higher overall loneliness (p = 0.026). Being married was related to a 36% (95% CI: 3%, 58%) reduction in emotional loneliness (p = 0.037). No musculoskeletal condition was associated with social isolation or loneliness. However, we observed a 22% (14%, 30%; p < 0.001) reduction in emotional loneliness and a 12% (4%, 20%; p = 0.003) reduction in overall loneliness per unit increase in self-efficacy score. CONCLUSIONS: No musculoskeletal condition was associated with increased social isolation or loneliness, but longitudinal studies in larger samples are required. Greater self-efficacy was associated with reduced social isolation and reduced loneliness. Interventions promoting self-efficacy in older adults may reduce isolation and loneliness in this age group.

Musculoskeletal health and life-space mobility in older adults: Findings from the Hertfordshire Cohort Study.

This study explores the relationship between musculoskeletal conditions of ageing and life-space mobility (LSM) in 1110 community-dwelling older adults from the Hertfordshire Cohort Study. LSM is a novel measure which captures ability to mobilise within the home, locally and more widely. Among men, older age, care receipt, not driving a car, lower wellbeing, and reduced physical function were associated with lower LSM, while in women only driving status and physical function were associated with LSM. Osteoporosis, arthritis, and fractures had no significant associations with LSM in either gender. These findings provide support for sex-specificity in the determinants of LSM and inform novel approaches to improving mobility and health in older age.

Do lifestyle, anthropometric and demographic factors associated with muscle strength differ in a UK and Japanese cohort? An exploratory analysis.

BACKGROUND: Muscle weakness is associated with adverse clinical outcomes including disability and mortality. We report demographic, anthropometric and lifestyle correlates of grip strength in UK and Japanese population-based cohorts. AIM: To report prevalence of low grip strength according to 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and 2019 Asian Working Group for Sarcopenia (AWGS 2019) thresholds and to consider correlates of grip strength in Eastern and Western populations. METHODS: UK (1572 men; 1415 women) and Japanese (519 men; 1027 women) participants were recruited from two cohorts harmonised by consensus. Muscle strength was measured by grip strength dynamometry. Potential correlates of grip strength were examined using sex-stratified linear regression; univariate correlates (p < 0.05) were included in mutually adjusted models. RESULTS: Mean (SD) age was 66.2 (2.8) and 65.8 (12.3) in UK and Japanese cohorts, respectively. Prevalence of low grip strength was higher in Japanese participants (EWGSOP2 5.4% versus 2.4%, AWGS 2019 9.0% versus 3.7%). In both cohorts and sexes, univariate correlates of lower grip strength were older age, shorter height, not consuming alcohol, leaving education earlier and greater comorbidity. Apart from older age and shorter height, the only factors related to lower grip strength in mutually adjusted analyses were greater comorbidity among UK participants (kg difference in grip strength (95%CI) per additional comorbidity - 0.60(- 0.98, - 0.21) among men and - 0.50(- 0.86, - 0.13) among women) and not consuming alcohol among Japanese men (- 1.33(- 2.51, - 0.15)). DISCUSSION: Correlates of muscle strength were similar in both cohorts. CONCLUSIONS: A global approach to age-related muscle weakness prevention may be appropriate.

DNA methylation of insulin signaling pathways is associated with HOMA2-IR in primary myoblasts from older adults.

BACKGROUND: While ageing is associated with increased insulin resistance (IR), the molecular mechanisms underlying increased IR in the muscle, the primary organ for glucose clearance, have yet to be elucidated in older individuals. As epigenetic processes are suggested to contribute to the development of ageing-associated diseases, we investigated whether differential DNA methylation was associated with IR in human primary muscle stem cells (myoblasts) from community-dwelling older individuals. METHODS: We measured DNA methylation (Infinium HumanMethylationEPIC BeadChip) in myoblast cultures from vastus lateralis biopsies (119 males/females, mean age 78.24 years) from the Hertfordshire Sarcopenia Study extension (HSSe) and examined differentially methylated cytosine phosphate guanine (CpG) sites (dmCpG), regions (DMRs) and gene pathways associated with HOMA2-IR, an index for the assessment of insulin resistance, and levels of glycated hemoglobin HbA1c. RESULTS: Thirty-eight dmCpGs (false discovery rate (FDR) < 0.05) were associated with HOMA2-IR, with dmCpGs enriched in genes linked with JNK, AMPK and insulin signaling. The methylation signal associated with HOMA2-IR was attenuated after the addition of either BMI (6 dmCpGs), appendicular lean mass index (ALMi) (7 dmCpGs), grip strength (15 dmCpGs) or gait speed (23 dmCpGs) as covariates in the model. There were 8 DMRs (Stouffer < 0.05) associated with HOMA2-IR, including DMRs within T-box transcription factor (TBX1) and nuclear receptor subfamily-2 group F member-2 (NR2F2); the DMRs within TBX1 and NR2F2 remained associated with HOMA2-IR after adjustment for BMI, ALMi, grip strength or gait speed. Forty-nine dmCpGs and 21 DMRs were associated with HbA1c, with cg13451048, located within exoribonuclease family member 3 (ERI3) associated with both HOMA2-IR and HbA1c. HOMA2-IR and HbA1c were not associated with accelerated epigenetic ageing. CONCLUSIONS: These findings suggest that insulin resistance is associated with differential DNA methylation in human primary myoblasts with both muscle mass and body composition making a significant contribution to the methylation changes associated with IR.

Hospital admissions and mortality over 20 years in community-dwelling older people: findings from the Hertfordshire Cohort Study.

BACKGROUND: Demographic changes worldwide are leading to pressures on health services, with hospital admissions representing an important contributor. Here, we report admission types experienced by older people and examine baseline risk factors for subsequent admission/death, from the community-based Hertfordshire Cohort Study. METHODS: 2997 participants (1418 women) completed a baseline questionnaire and clinic visit to characterize their health. Participants were followed up from baseline (1998-2004, aged 59-73 years) until December 2018 using UK Hospital Episode Statistics and mortality data, which report clinical outcomes using ICD-10 coding. Baseline characteristics in relation to the risk of admission/death during follow-up were examined using sex-stratified univariate logistic regression. RESULTS: During follow-up, 36% of men and 26% of women died and 93% of men and 92% of women had at least one hospital admission; 6% of men and 7% of women had no admissions and were alive at end of follow-up. The most common types of admission during follow-up were cardiovascular (ever experienced: men 71%, women 68%) and respiratory (men 40%, women 34%). In both sexes, baseline risk factors that were associated (p < 0.05) with admission/death during follow-up were older age, poorer SF-36 physical function, and poorer self-rated health. In men, manual social class and a history of smoking, and in women, higher BMI, not owning one's home, and a minor trauma fracture since age 45, were also risk factors for admission/death. CONCLUSIONS: Sociodemographic factors were related to increased risk of admission/death but a small proportion experienced no admissions during this period, suggesting that healthy ageing is achievable.

Machine learning as an adjunct to expert observation in classification of radiographic knee osteoarthritis: findings from the Hertfordshire Cohort Study.

BACKGROUND: Osteoarthritis is the most prevalent type of arthritis. Many approaches exist for characterising radiographic knee OA, including machine learning (ML). AIMS: To examine Kellgren and Lawrence (K&L) scores from ML and expert observation, minimum joint space and osteophyte in relation to pain and function. METHODS: Participants from the Hertfordshire Cohort Study, comprising individuals born in Hertfordshire from 1931 to 1939, were analysed. Radiographs were assessed by clinicians and ML (convolutional neural networks) for K&L scoring. Medial minimum joint space and osteophyte area were ascertained using the knee OA computer-aided diagnosis (KOACAD) program. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was administered. Receiver operating characteristic analysis was implemented for minimum joint space, osteophyte, and observer- and ML-derived K&L scores in relation to pain (WOMAC pain score > 0) and impaired function (WOMAC function score > 0). RESULTS: 359 participants (aged 71-80) were analysed. Among both sexes, discriminative capacity regarding pain and function was fairly high for observer-derived K&L scores [area under curve (AUC): 0.65 (95% CI 0.57, 0.72) to 0.70 (0.63, 0.77)]; results were similar among women for ML-derived K&L scores. Discriminative capacity was moderate among men for minimum joint space in relation to pain [0.60 (0.51, 0.67)] and function [0.62 (0.54, 0.69)]. AUC < 0.60 for other sex-specific associations. DISCUSSION: Observer-derived K&L scores had higher discriminative capacity regarding pain and function compared to minimum joint space and osteophyte. Among women, discriminative capacity was similar for observer- and ML-derived K&L scores. CONCLUSION: ML as an adjunct to expert observation for K&L scoring may be beneficial due to the efficiency and objectivity of ML.

Recent sarcopenia definitions-prevalence, agreement and mortality associations among men: Findings from population-based cohorts.

BACKGROUND: The 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definitions and Outcomes Consortium (SDOC) have recently proposed sarcopenia definitions. However, comparisons of the performance of these approaches in terms of thresholds employed, concordance in individuals and prediction of important health-related outcomes such as death are limited. We addressed this in a large multinational assembly of cohort studies that included information on lean mass, muscle strength, physical performance and health outcomes. METHODS: White men from the Health Aging and Body Composition (Health ABC) Study, Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, USA), the Hertfordshire Cohort Study (HCS) and the Sarcopenia and Physical impairment with advancing Age (SarcoPhAge) Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over courses of 2.4-6 m. Deaths were recorded and verified. Definitions of sarcopenia were as follows: EWGSOP2 (grip strength <27 kg and ALM index <7.0 kg/m2 ), SDOC (grip strength <35.5 kg and gait speed <0.8 m/s) and Modified SDOC (grip strength <35.5 kg and gait speed <1.0 m/s). Cohen's kappa statistic was used to assess agreement between original definitions (EWGSOP2 and SDOC). Presence versus absence of sarcopenia according to each definition in relation to mortality risk was examined using Cox regression with adjustment for age and weight; estimates were combined across cohorts using random-effects meta-analysis. RESULTS: Mean (SD) age of participants (n = 9170) was 74.3 (4.9) years; 5929 participants died during a mean (SD) follow-up of 12.1 (5.5) years. The proportion with sarcopenia according to each definition was EWGSOP2 (1.1%), SDOC (1.7%) and Modified SDOC (5.3%). Agreement was weak between EWGSOP2 and SDOC (κ = 0.17). Pooled hazard ratios (95% CI) for mortality for presence versus absence of each definition were EWGSOP2 [1.76 (1.42, 2.18), I2 : 0.0%]; SDOC [2.75 (2.28, 3.31), I2 : 0.0%]; and Modified SDOC [1.93 (1.54, 2.41), I2 : 58.3%]. CONCLUSIONS: There was low prevalence and poor agreement among recent sarcopenia definitions in community-dwelling cohorts of older white men. All indices of sarcopenia were associated with mortality. The strong relationship between sarcopenia and mortality, regardless of the definition, illustrates that identification of appropriate management and lifecourse intervention strategies for this condition is of paramount importance.

Investigating the relationship between self-perception of fracture risk and prior fracture: findings from the Hertfordshire Cohort Study.

BACKGROUND: Self-perceived risk of fracture (SPR) is associated with fracture independent of FRAX calculated risk. To understand this better we considered whether lifestyle factors not included in the FRAX algorithm and psychosocial factors (social isolation, self-efficacy, or mental health status) explain the relationship between SPR and fracture. METHODS: We studied 146 UK community-dwelling older adults from the Hertfordshire Cohort Study. SPR ranked as 'lower', 'similar' and 'higher' relative to others of the same age, was assessed by questionnaire. Social isolation was assessed using the six-item Lubben Social Network Scale; self-efficacy was assessed using a shortened General Self-Efficacy Scale (GSE); mental health status was assessed using the anxiety/depression item from the EuroQoL questionnaire. SPR in relation to previous self-reported fracture was examined using logistic regression. RESULTS: Among participants of median age 83.4 (IQR 81.5-85.5) years, SPR was lower for 54.1% of participants, similar for 30.8%, and higher for 15.1%; 74.7% reported no previous fractures. Greater SPR was associated with increased odds of previous fractures when adjusting for sex and age only (OR 1.72, 95% CI 1.03-2.87, per higher band of SPR). While further individual adjustment for social isolation (1.73, 1.04-2.89), self-efficacy (1.71, 1.02-2.85), or mental health (1.77, 1.06-2.97) did not attenuate the relationship, individual adjustment for diet quality and number of comorbidities did. CONCLUSIONS: Adjustment for social isolation, self-efficacy or mental health status did not attenuate the relationship between SPR and fracture. By contrast, lifestyle factors not included in FRAX, such as diet quality, did attenuate relationships, suggesting a possible future area of investigation.

Machine learning applied to HR-pQCT images improves fracture discrimination provided by DXA and clinical risk factors.

BACKGROUND: Traditional analysis of High Resolution peripheral Quantitative Computed Tomography (HR-pQCT) images results in a multitude of cortical and trabecular parameters which would be potentially cumbersome to interpret for clinicians compared to user-friendly tools utilising clinical parameters. A computer vision approach (by which the entire scan is 'read' by a computer algorithm) to ascertain fracture risk, would be far simpler. We therefore investigated whether a computer vision and machine learning technique could improve upon selected clinical parameters in assessing fracture risk. METHODS: Participants of the Hertfordshire Cohort Study (HCS) attended research visits at which height and weight were measured; fracture history was determined via self-report and vertebral fracture assessment. Bone microarchitecture was assessed via HR-pQCT scans of the non-dominant distal tibia (Scanco XtremeCT), and bone mineral density measurement and lateral vertebral assessment were performed using dual-energy X-ray absorptiometry (DXA) (Lunar Prodigy Advanced). Images were cropped, pre-processed and texture analysis was performed using a three-dimensional local binary pattern method. These image data, together with age, sex, height, weight, BMI, dietary calcium and femoral neck BMD, were used in a random-forest classification algorithm. Receiver operating characteristic (ROC) analysis was used to compare fracture risk identification methods. RESULTS: Overall, 180 males and 165 females were included in this study with a mean age of approximately 76 years and 97 (28 %) participants had sustained a previous fracture. Using clinical risk factors alone resulted in an area under the curve (AUC) of 0.70 (95 % CI: 0.56-0.84), which improved to 0.71 (0.57-0.85) with the addition of DXA-measured BMD. The addition of HR-pQCT image data to the machine learning classifier with clinical risk factors and DXA-measured BMD as inputs led to an improved AUC of 0.90 (0.83-0.96) with a sensitivity of 0.83 and specificity of 0.74. CONCLUSION: These results suggest that using a three-dimensional computer vision method to HR-pQCT scanning may enhance the identification of those at risk of fracture beyond that afforded by clinical risk factors and DXA-measured BMD. This approach has the potential to make the information offered by HR-pQCT more accessible (and therefore) applicable to healthcare professionals in the clinic if the technology becomes more widely available.

What impact does osteoarthritis have on ability to self-care and receipt of care in older adults? Findings from the Hertfordshire Cohort Study.

Objectives: Living independently remains the aim of older adults, but musculoskeletal conditions and frailty may hamper this. We examined relationships between osteoarthritis with ability to self-care and access to formal/informal care among community-dwelling older adults, comparing results to relationships between other musculoskeletal conditions of ageing (frailty, sarcopenia, osteoporosis) and these outcomes. Design: Data from the Hertfordshire Cohort Study were used. Osteoarthritis (hand, hip or knee) was defined by clinical examination. Osteoporosis was assessed using dual-energy X-ray absorptiometry and medication use. Sarcopenia was assessed using EWSGOP2 criteria, frailty using Fried criteria. Ability to self-care and access to formal/informal care were self-reported. Results: 443 men and women aged approximately 75 years participated. Osteoarthritis was reported by 26.8% participants; 11.8% had low grip strength; 21.4% had osteoporosis; 8.6% had sarcopenia; 7.6% were identified as frail. Most participants (90.7%) reported no problems with self-care, but more than one-fifth (21.4%) reported having received formal or informal care at home in the previous year. Odds of reporting difficulties with self-care were significantly greater (p â€‹< â€‹0.05) for participants with osteoarthritis and for those with frailty, but not for those with osteoporosis or sarcopenia. Odds of receiving care at home in the past year were significantly greater among participants with osteoarthritis and among those with frailty, but not among those with osteoporosis or sarcopenia. Conclusions: Frailty and osteoarthritis were associated with both difficulties with self-care and receipt of care; osteoporosis and sarcopenia were not. These results highlight the contribution of clinical osteoarthritis to ability to live independently in later life, and the need to actively manage the condition in older adults.

Determinants of muscle density and clinical outcomes: Findings from the Hertfordshire Cohort Study.

PURPOSE: The age-related loss of skeletal muscle mass and strength is associated with adverse health outcomes. However, to date, peripheral quantitative computed tomography (pQCT)-derived muscle density has been little studied. We used a well characterised cohort of older adults to identify lifestyle and anthropometric determinants of pQCT-derived muscle density measured 11 years later, and to report relationships between pQCT-derived muscle density with history of falls and prevalent fractures. METHODS: A lifestyle questionnaire was administered to 197 men and 178 women, aged 59-70 at baseline. After a median of 11.5 (IQR 10.9, 12.3) years, pQCT (Stratec XCT2000) of the radius and tibia was performed to measure forearm muscle density (FMD) and calf muscle density (CMD). Presence of falls and fractures since the age of 45 were determined through participant recall; vertebral fractures were also ascertained through vertebral fracture assessment using iDXA. Total hip BMD (TH aBMD) was assessed using DXA. Baseline characteristics in relation to muscle density at follow-up were examined using linear regression; associations between muscle density and prior falls and fractures were investigated using logistic regression. All analyses were adjusted for sex and age. RESULTS: Mean (SD) age at muscle density measurement was 76.3 (2.6) years. Mean (SD) FMD was 79.9 (3.1) and 77.2 (3.2) among males and females, respectively; CMD was 80.7 (2.6) and 78.5 (2.6) among males and females, respectively. Significant sex-differences in muscle density were observed at each site (p < 0.001). Female sex, lower weight, and lower body mass index were associated (p < 0.05) with both lower FMD and CMD. Additional correlates of lower CMD included older age and shorter stature. Lifestyle measures were not associated with muscle density in this cohort. Lower FMD was related to increased risk of previous fracture (odds ratio (95 % CI) per SD lower FMD: 1.42 (1.07, 1.89), p = 0.015) but not after adjustment for TH aBMD (p > 0.08). No significant relationships were seen between muscle density and falls. CONCLUSION: Female sex, older age, and lower BMI were associated with subsequent lower muscle density in older community-dwelling adults. Lower FMD was related to increased risk of previous fracture. Changes in muscle density over time might precede adverse outcomes such as falls and fractures and may be a long-term predictor of frailty. It could be also suggested that muscle density could be a more clinically meaningful surrogate of functional decline and disability than muscle size or mass, but more studies are needed to support this notion.

Relationships Between Muscle Parameters and History of Falls and Fractures in the Hertfordshire Cohort Study: Do All Muscle Components Relate Equally to Clinical Outcomes?

In previous work, relationships between muscle and bone size and strength have been demonstrated and were stronger in females, suggesting possible sexual dimorphism. Here we examine sex-specific associations between individual muscle sarcopenia components with clinical outcomes (falls and fractures). 641 participants were recruited. Muscle mass was assessed as cross-sectional area (CSA) by peripheral quantitative computed tomography of the calf, grip strength (GpS) by Jamar dynamometry and function by gait speed (GtS). Falls and fractures were self-reported. Ordinal and logistic regression were used to examine the associations between muscle measurements and outcomes with and without adjustment for confounders. Mean (SD) age was 69.3 (2.6) years. CSA, GpS, and GtS were greater among males (p < 0.002). A higher proportion of females had fallen since age 45 (61.3% vs 40.2%, p < 0.001); in the last year (19.9% vs 14.1%, p = 0.053); and reported a previous fracture since age 45 (21.8% vs 18.5%, p = 0.302), than males. Among females, greater CSA was related to reduced risk of falling and fewer falls in the previous year in fully adjusted analysis only (p < 0.05); higher GpS was related to lower risk of falls since age 45 in unadjusted analysis (p = 0.045) and lower risk of fracture since age 45 in both unadjusted and fully adjusted analysis (p < 0.045). No statistically significant associations were observed for GtS among either sex for any relationships between muscle measurements and clinical outcomes studied. We observed relationships between muscle mass and strength but not function with falls and fractures in females only; further longitudinal studies are required to reproduce these results.

Epigenome-wide association study of sarcopenia: findings from the Hertfordshire Sarcopenia Study (HSS).

BACKGROUND: Sarcopenia is the age-related loss of muscle mass, strength, and function. Epigenetic processes such as DNA methylation, which integrate both genetic and environmental exposures, have been suggested to contribute to the development of sarcopenia. This study aimed to determine whether differences in the muscle methylome are associated with sarcopenia and its component measures: grip strength, appendicular lean mass index (ALMi), and gait speed. METHODS: Using the Infinium Human MethylationEPIC BeadChip, we measured DNA methylation in vastus lateralis muscle biopsies of 83 male participants (12 with sarcopenia) with a mean (standard deviation) age of 75.7 (3.6) years from the Hertfordshire Sarcopenia Study (HSS) and Hertfordshire Sarcopenia Study extension (HSSe) and examined associations with sarcopenia and its components. Pathway, histone mark, and transcription factor enrichment of the differentially methylated CpGs (dmCpGs) were determined, and sodium bisulfite pyrosequencing was used to validate the sarcopenia-associated dmCpGs. Human primary myoblasts (n = 6) isolated from vastus lateralis muscle biopsies from male individuals from HSSe were treated with the EZH2 inhibitor GSK343 to assess how perturbations in epigenetic processes may impact myoblast differentiation and fusion, measured by PAX7 and MYHC immunocytochemistry, and mitochondrial bioenergetics determined using the Seahorse XF96. RESULTS: Sarcopenia was associated with differential methylation at 176 dmCpGs (false discovery rate ≤ 0.05) and 141 differentially methylated regions (Stouffer ≤ 0.05). The sarcopenia-associated dmCpGs were enriched in genes associated with myotube fusion (P = 1.40E-03), oxidative phosphorylation (P = 2.78E-02), and voltage-gated calcium channels (P = 1.59E-04). ALMi was associated with 71 dmCpGs, grip strength with 49 dmCpGs, and gait speed with 23 dmCpGs (false discovery rate ≤ 0.05). There was significant overlap between the dmCpGs associated with sarcopenia and ALMi (P = 3.4E-35), sarcopenia and gait speed (P = 4.78E-03), and sarcopenia and grip strength (P = 7.55E-06). There was also an over-representation of the sarcopenia, ALMi, grip strength, and gait speed-associated dmCpGs with sites of H3K27 trimethylation (all P ≤ 0.05) and amongst EZH2 target genes (all P ≤ 0.05). Furthermore, treatment of human primary myoblasts with the EZH2 inhibitor GSK343 inhibitor led to an increase in PAX7 expression (P ≤ 0.05), decreased myotube fusion (P = 0.043), and an increase in ATP production (P = 0.008), with alterations in the DNA methylation of genes involved in oxidative phosphorylation and myogenesis. CONCLUSIONS: These findings show that differences in the muscle methylome are associated with sarcopenia and individual measures of muscle mass, strength, and function in older individuals. This suggests that changes in the epigenetic regulation of genes may contribute to impaired muscle function in later life.

A study of diet in older community-dwelling adults in the UK during the COVID-19 pandemic: Findings from the Southampton Longitudinal Study of Ageing (SaLSA).

Introduction: Adequate nutrition is important for health in later life. Older adults are especially vulnerable to adverse outcomes following infection by COVID-19 and have commonly spent a disproportionate time within their own homes to reduce risk of infection. There are concerns that advice to shield may have led to malnutrition as older adults may modify daily routines including usual shopping habits. The aims of this study were to report self-reported pandemic-related changes in diet and examine lifestyle and medical correlates of these changes in older UK community-dwelling adults. Methods: We recruited 491 participants from the city of Southampton, UK. Participants completed a postal questionnaire in summer/autumn 2021, over a year after the first UK national lockdown was announced. The questionnaire ascertained demographic and lifestyle factors, in addition to number of comorbidities, nutrition risk scores, and presence of frailty. Associations between these participant characteristics in relation to self-reported changes in diet quality (lower, similar or higher when compared to before the first lockdown) were examined using ordinal logistic regression. Results: Median (lower quartile, upper quartile) age was 79.8 (77.0, 83.7) years. Overall, 11 (4.9%) men and 25 (9.4%) women had poorer diet quality compared to before the first UK lockdown. The following participant characteristics were associated with increased risk of being in a worse category for change in diet quality after adjustment for sex: lower educational attainment (p = 0.009); higher BMI (p < 0.001); higher DETERMINE (a malnutrition assessment) score (p = 0.004); higher SARC-F score (p = 0.013); and self-reported exhaustion in the previous week on at least 3 days (p = 0.002). Conclusions: Individuals at higher nutritional risk were identified as reporting increased risk of deterioration in diet quality during the pandemic. Further investigation of the factors leading to these changes, and an understanding of whether they are reversible will be important, especially for future pandemic management.

Is lifestyle change around retirement associated with better physical performance in older age?: insights from a longitudinal cohort.

A growing evidence base links individual lifestyle factors to physical performance in older age, but much less is known about their combined effects, or the impact of lifestyle change. In a group of 937 participants from the MRC National Survey of Health and Development, we examined their number of lifestyle risk factors at 53 and 60-64 years in relation to their physical performance at 60-64, and the change in number of risk factors between these ages in relation to change in physical performance. At both assessments, information about lifestyle (physical activity, smoking, diet) was obtained via self-reports and height and weight were measured. Each participant's number of lifestyle risk factors out of: obesity (body mass index ≥ 30 kg/m2); inactivity (no leisure time physical activity over previous month); current smoking; poor diet (diet quality score in bottom quarter of distribution) was determined at both ages. Physical performance: measured grip strength, chair rise and standing balance times at both ages and conditional change (independent of baseline) in physical performance outcomes from 53 to 60-64 were assessed. There were some changes in the pattern of lifestyle risk factors between assessments: 227 (24%) participants had fewer risk factors by age 60-64; 249 (27%) had more. Reductions in risk factors were associated with better physical performance at 60-64 and smaller declines over time (all p < 0.05); these associations were robust to adjustment. Strategies to support reduction in number of lifestyle risk factors around typical retirement age may have beneficial effects on physical performance in early older age. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s10433-021-00607-9) contains supplementary material, which is available to authorized users.