Timing of objectively-collected physical activity in relation to body weight and metabolic health in sedentary older people: a cross-sectional and prospective analysis.

BACKGROUND: Little is known about the impact of timing as opposed to frequency and intensity of daily physical activity on metabolic health. Therefore, we assessed the association between accelerometery-based daily timing of physical activity and measures of metabolic health in sedentary older people. METHODS: Hourly mean physical activity derived from wrist-worn accelerometers over a 6-day period was collected at baseline and after 3 months in sedentary participants from the Active and Healthy Ageing study. A principal component analysis (PCA) was performed to reduce the number of dimensions (e.g. define periods instead of separate hours) of hourly physical activity at baseline and change during follow-up. Cross-sectionally, a multivariable-adjusted linear regression analysis was used to associate the principal components, particularly correlated with increased physical activity in data-driven periods during the day, with body mass index (BMI), fasting glucose and insulin, HbA1c and the homeostatic model assessment for insulin resistance (HOMA-IR). For the longitudinal analyses, we calculated the hourly changes in physical activity and change in metabolic health after follow-up. RESULTS: We included 207 individuals (61.4% male, mean age: 64.8 [SD 2.9], mean BMI: 28.9 [4.7]). Higher physical activity in the early morning was associated with lower fasting glucose (-2.22%, 95% CI: -4.19, -0.40), fasting insulin (-13.54%, 95%CI: -23.49, -4.39), and HOMA-IR (-16.07%, 95%CI: -27.63, -5.65). Higher physical activity in the late afternoon to evening was associated with lower BMI (-2.84%, 95% CI: -4.92, -0.70). Higher physical activity at night was associated with higher BMI (2.86%, 95% CI: 0.90, 4.78), fasting glucose (2.57%, 95% CI: 0.70, 4.30), and HbA1c (2.37%, 95% CI: 1.00, 3.82). Similar results were present in the prospective analysis. CONCLUSION: Specific physical activity timing patterns were associated with more beneficial metabolic health, suggesting particular time-dependent physical activity interventions might maximise health benefits.

Investigating the relationships between unfavourable habitual sleep and metabolomic traits: evidence from multi-cohort multivariable regression and Mendelian randomization analyses.

BACKGROUND: Sleep traits are associated with cardiometabolic disease risk, with evidence from Mendelian randomization (MR) suggesting that insomnia symptoms and shorter sleep duration increase coronary artery disease risk. We combined adjusted multivariable regression (AMV) and MR analyses of phenotypes of unfavourable sleep on 113 metabolomic traits to investigate possible biochemical mechanisms linking sleep to cardiovascular disease. METHODS: We used AMV (N = 17,368) combined with two-sample MR (N = 38,618) to examine effects of self-reported insomnia symptoms, total habitual sleep duration, and chronotype on 113 metabolomic traits. The AMV analyses were conducted on data from 10 cohorts of mostly Europeans, adjusted for age, sex, and body mass index. For the MR analyses, we used summary results from published European-ancestry genome-wide association studies of self-reported sleep traits and of nuclear magnetic resonance (NMR) serum metabolites. We used the inverse-variance weighted (IVW) method and complemented this with sensitivity analyses to assess MR assumptions. RESULTS: We found consistent evidence from AMV and MR analyses for associations of usual vs. sometimes/rare/never insomnia symptoms with lower citrate (- 0.08 standard deviation (SD)[95% confidence interval (CI) - 0.12, - 0.03] in AMV and - 0.03SD [- 0.07, - 0.003] in MR), higher glycoprotein acetyls (0.08SD [95% CI 0.03, 0.12] in AMV and 0.06SD [0.03, 0.10) in MR]), lower total very large HDL particles (- 0.04SD [- 0.08, 0.00] in AMV and - 0.05SD [- 0.09, - 0.02] in MR), and lower phospholipids in very large HDL particles (- 0.04SD [- 0.08, 0.002] in AMV and - 0.05SD [- 0.08, - 0.02] in MR). Longer total sleep duration associated with higher creatinine concentrations using both methods (0.02SD per 1 h [0.01, 0.03] in AMV and 0.15SD [0.02, 0.29] in MR) and with isoleucine in MR analyses (0.22SD [0.08, 0.35]). No consistent evidence was observed for effects of chronotype on metabolomic measures. CONCLUSIONS: Whilst our results suggested that unfavourable sleep traits may not cause widespread metabolic disruption, some notable effects were observed. The evidence for possible effects of insomnia symptoms on glycoprotein acetyls and citrate and longer total sleep duration on creatinine and isoleucine might explain some of the effects, found in MR analyses of these sleep traits on coronary heart disease, which warrant further investigation.

Differential insulin sensitivity of NMR-based metabolomic measures in a two-step hyperinsulinemic euglycemic clamp study.

BACKGROUND: Insulin is the key regulator of glucose metabolism, but it is difficult to dissect direct insulin from glucose-induced effects. We aimed to investigate the effects of hyperinsulemia on metabolomic measures under euglycemic conditions in nondiabetic participants. METHODS: We assessed concentrations of 151 metabolomic measures throughout a two-step hyperinsulinemic euglycemic clamp procedure. We included 24 participants (50% women, mean age = 62 [s.d. = 4.2] years) and metabolomic measures were assessed under baseline, low-dose (10 mU/m2/min) and high-dose (40 mU/m2/min) insulin conditions. The effects of low- and high-dose insulin infusion on metabolomic measures were analyzed using linear mixed-effect models for repeated measures. RESULTS: After low-dose insulin infusion, 90 metabolomic measures changed in concentration (p < 1.34e-4), among which glycerol (beta [Confidence Interval] = - 1.41 [- 1.54, - 1.27] s.d., p = 1.28e-95) and three-hydroxybutyrate (- 1.22 [- 1.36, - 1.07] s.d., p = 1.44e-61) showed largest effect sizes. After high-dose insulin infusion, 121 metabolomic measures changed in concentration, among which branched-chain amino acids showed the largest additional decrease compared with low-dose insulin infusion (e.g., Leucine, - 1.78 [- 1.88, - 1.69] s.d., P = 2.7e-295). More specifically, after low- and high-dose insulin infusion, the distribution of the lipoproteins shifted towards more LDL-sized particles with decreased mean diameters. CONCLUSION: Metabolomic measures are differentially insulin sensitive and may thus be differentially affected by the development of insulin resistance. Moreover, our data suggests insulin directly affects metabolomic measures previously associated with increased cardiovascular disease risk.

An Internet-Based Physical Activity Intervention to Improve Quality of Life of Inactive Older Adults: A Randomized Controlled Trial.

BACKGROUND: Increasing physical activity is a viable strategy for improving both the health and quality of life of older adults. OBJECTIVE: The aim of this study was to assess if an Internet-based intervention aimed to increase physical activity was effective in improving quality of life of inactive older adults. In addition, we analyzed the effect of the intervention on quality of life among those participants who successfully reached their individually targeted increase in daily physical activity as indicated by the intervention program, as well as the dose-response effect of increasing physical activity on quality of life. METHODS: The intervention was tested in a randomized controlled trial and was comprised of an Internet program-DirectLife (Philips)-aimed at increasing physical activity using monitoring and feedback by accelerometry and feedback by digital coaching (n=119). The control group received no intervention (n=116). Participants were inactive 60-70-year-olds and were recruited from the general population. Quality of life and physical activity were measured at baseline and after 3 months using the Research ANd Development 36-item health survey (RAND-36) and wrist-worn triaxial accelerometer, respectively. RESULTS: After 3 months, a significant improvement in quality of life was seen in the intervention group compared to the control group for RAND-36 subscales on emotional and mental health (2.52 vs -0.72, respectively; P=.03) and health change (8.99 vs 2.03, respectively; P=.01). A total of 50 of the 119 participants (42.0%) in the intervention group successfully reached their physical activity target and showed a significant improvement in quality of life compared to the control group for subscales on emotional and mental health (4.31 vs -0.72, respectively; P=.009) and health change (11.06 vs 2.03, respectively; P=.004). The dose-response analysis showed that there was a significant association between increase in minutes spent in moderate-to-vigorous physical activity (MVPA) and increase in quality of life. CONCLUSIONS: Our study shows that an Internet-based physical activity program was effective in improving quality of life in 60-70-year-olds after 3 months, particularly in participants that reached their individually targeted increase in daily physical activity. TRIAL REGISTRATION: Nederlands Trial Register: NTR 3045; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3045 (Archived by WebCite at http://www.webcitation.org/6fobg2sjJ).

Dose-response effects of a Web-based physical activity program on body composition and metabolic health in inactive older adults: additional analyses of a randomized controlled trial.

BACKGROUND: Low physical activity is a major risk factor for several age-related diseases. Recently, we showed in a randomized controlled trial that a 12-week Web-based intervention (Philips DirectLife) to increase physical activity was effective in increasing physical activity levels and metabolic health in an inactive population aged 60-70 years. OBJECTIVE: The goal of this paper was to assess how many participants successfully reached the physical activity level as targeted by the intervention and what the effects of the intervention on body composition and metabolic health in these successful individuals were to provide insight in the maximum attainable effect of the intervention. METHODS: Among the 235 participants in a randomized controlled trial of the Actief en Gezond Oud (AGO) study, we assessed the effects of the intervention on metabolic parameters in those who had successfully reached their personalized physical activity target compared with the entire intervention group. Furthermore, we studied the dose-response effect of increase in physical activity on metabolic outcome within the intervention group. RESULTS: Of the intervention group, 50 of 119 (42.0%) participants successfully reached the physical activity target (corresponding to a 10% increased daily physical activity on average). This group showed markedly higher effects of the intervention compared to the entire intervention group, with greater decreases in body weight (2.74 vs 1.49 kg), waist circumference (3.74 vs 2.33 cm), insulin resistance (HOMA index: 0.23 vs 0.20), and in cholesterol/HDL ratio (0.39 vs 0.20) and Framingham risk score (0.90% vs 0.54%). We found that men compared to women were more likely to be successful. The dose-response analysis showed that there was a significant association between increase in minutes spent in moderate-to-vigorous activity and body weight loss, BMI reduction, waist circumference reduction, HDL cholesterol increasing, and cholesterol/HDL ratio lowering. CONCLUSIONS: Of the intervention group, 42.0% (50/119) reached their daily physical activity end goal, which was associated with a markedly better effect on body composition and metabolic health compared to the effect in the entire intervention group. In this population, men are more likely to be successful in increasing physical activity. Findings demonstrate that improving the effect of such physical activity interventions requires finding new ways to increase the proportion of the population reaching the targeted goal. TRIAL REGISTRATION: Dutch Trial Registry: NTR 3045; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3045 (Archived by WebCite at http://www.webcitation.org/6KPw52dCc).

Effects of a web-based intervention on physical activity and metabolism in older adults: randomized controlled trial.

BACKGROUND: Lack of physical activity leads to detrimental changes in body composition and metabolism, functional decline, and increased risk of disease in old age. The potential of Web-assisted interventions for increasing physical activity and improving metabolism in older individuals holds great promise but to our knowledge it has not been studied. OBJECTIVE: The goal of our study was to assess whether a Web-based intervention increases physical activity and improves metabolic health in inactive older adults. METHODS: We conducted a 3-month randomized, waitlist-controlled trial in a volunteer sample of 235 inactive adults aged 60-70 years without diabetes. The intervention group received the Internet program Philips DirectLife, which was directed at increasing physical activity using monitoring and feedback by accelerometer and digital coaching. The primary outcome was relative increase in physical activity measured objectively using ankle- and wrist-worn accelerometers. Secondary outcomes of metabolic health included anthropometric measures and parameters of glucose metabolism. RESULTS: In total, 226 participants (97%) completed the study. At the ankle, activity counts increased by 46% (standard error [SE] 7%) in the intervention group, compared to 12% (SE 3%) in the control group (P(difference)<.001). Measured at the wrist, activity counts increased by 11% (SE 3%) in the intervention group and 5% (SE 2%) in the control group (P(difference)=.11). After processing of the data, this corresponded to a daily increase of 11 minutes in moderate-to-vigorous activity in the intervention group versus 0 minutes in the control group (P(difference)=.001). Weight decreased significantly more in the intervention group compared to controls (-1.5 kg vs -0.8 kg respectively, P=.046), as did waist circumference (-2.3 cm vs -1.3 cm respectively, P=.036) and fat mass (-0.6% vs 0.07% respectively, P=.025). Furthermore, insulin and HbA1c levels were significantly more reduced in the intervention group compared to controls (both P<.05). CONCLUSIONS: This was the first study to show that in inactive older adults, a 3-month Web-based physical activity intervention was effective in increasing objectively measured daily physical activity and improving metabolic health. Such Web-based interventions provide novel opportunities for large scale prevention of metabolic deregulation in our rapidly aging population.

High Adiposity Is Associated With Higher Nocturnal and Diurnal Glycaemia, but Not With Glycemic Variability in Older Individuals Without Diabetes.

BACKGROUND: It is well known that adiposity is a risk factor for insulin resistance and type 2 diabetes mellitus. In the present study, we aimed to investigate the associations of measures of adiposity with indices of glycemia and of glycemic variability over a 72-h period in non-diabetic older adults. METHODS: This cross-sectional study was conducted in non-diabetic individuals from the Active and Healthy Aging Study (N = 228), Switchbox (N = 116), and the Growing Old Together Study (N = 94). Body mass index (BMI) and waist circumference were measured, and indices of glycemia and glycemic variability were derived from continuous glucose monitoring (CGM) using the Mini-Med® CGM system. Associations between adiposity and CGM were studied separately for the three cohorts, and derived estimates were subsequently meta-analyzed. RESULTS: After meta-analyzing the results from the separate cohorts, individuals with a higher BMI had higher levels of glycemia. Individuals with BMI between 30 and 35 kg/m2 had 0.28 mmol/L [95% confidence interval (CI): 0.12-0.44] higher 72 h-mean glucose concentration, 0.26 mmol/L (0.10-0.42) higher diurnal glucose (6:00 a.m. to 0:00 a.m.), and 0.39 mmol/L (0.19; 0.59) higher nocturnal glucose (3:00 a.m. to 6:00 a.m.) than participants with a normal weight (BMI 18.5-25 kg/m2). However, no associations were observed between higher BMI and glycemic variability. Results for glycemia and glycemic variability were similarly observed for a high waist circumference. CONCLUSION: High adiposity associates with constant higher mean glucose levels over the day in non-diabetic older adults.

Association between the rs7903146 Polymorphism in the TCF7L2 Gene and Parameters Derived with Continuous Glucose Monitoring in Individuals without Diabetes.

BACKGROUND: The rs7903146-T allele in the transcription factor 7-like 2 (TCF7L2) gene has been associated with impaired pancreatic insulin secretion, enhanced liver glucose production, and an increased risk of type 2 diabetes. Nevertheless, the impact of rs7903146 on daily glucose trajectories remains unclear. Continuous glucose monitoring (CGM) can estimate glycemia and glycemic variability based on consecutive glucose measurements collected over several days. The purpose of the present study was to investigate the associations of rs7903146 with glycemia and glycemic variability in middle-aged participants without diabetes. METHODS: Complete data from 235 participants without diabetes from the Leiden Longevity Study were available. Participants were divided into two groups based on rs7903146 genotype; rs7903146-CC genotype carriers (N = 123) and rs7903146-CT/TT genotype carriers (N = 112). Validated parameters of glycemia (e.g., mean 24h glucose level) and glycemic variability (e.g., 24h standard deviation) were derived from data collected with a CGM system for a 72-hour period. RESULTS: The study population was on average 64.7 years old (standard deviation = 5.9) and composed of 49.8% of women. Compared with rs7903146-CC carriers, rs7903146-CT/TT carriers exhibited a trend towards a higher mean 24-hour glucose level (5.21 versus 5.32 mmol/L; p-value = 0.15) and a significantly higher mean nocturnal glucose (3:00am- 6:00am; 4.48 versus 4.67 mmol/L; p-value = 0.03) that was explained for 34.6% by body weight and percentage body fat. No differences in measures of glycemic variability between the genotype groups were observed. CONCLUSION: Despite limited sample size, our study indicates that the rs7903146-T allele in TCF7L2 was associated with a higher mean nocturnal glucose dependent on body composition, which might suggest that rs7902146 affects liver-specific aspects of glucose metabolism.

Renal function in familial longevity: the Leiden Longevity Study.

Studying renal function in subjects with a familial propensity for longevity may provide insight in (un)known mechanisms that determine the age-related decline in renal function of normal subjects. In the Leiden Longevity Study, middle-aged offspring of non-agenarian siblings and their partners as environmentally matched controls were included. Information was collected on lifestyle, medical history, medication use, and a non-fasting blood sample was drawn. Renal function (estimated glomerular filtration rate, eGFR) was assessed with the Chronic Kidney Disease epidemiology collaboration (CKD-EPI) formula. Linear mixed models were used to account for familial dependencies within the offspring and all analyses were stratified by sex. eGFR was similar between female offspring and female controls (0.44ml/min/1.73m(2) (SE 0.72) difference, p=0.54, age-adjusted). Male offspring had a higher eGFR compared to male controls (1.78ml/min/1.73m(2) (SE 0.78) difference, p=0.022, age-adjusted), and further adjustments for various characteristics did not materially change this difference. Among men with a history of hypertension, or myocardial infarction and/or stroke, offspring had a higher eGFR compared to controls (4.74ml/min/1.73m(2) (SE 1.53) difference, p=0.002, age-adjusted, and 6.21ml/min/1.73m(2) (SE 2.85) difference, p=0.033, age-adjusted, respectively). Middle-aged men, but not women, with a propensity for longevity have better renal function compared to environmentally matched controls, especially among those with a history of cardiovascular disease.

Ambulant 24-h glucose rhythms mark calendar and biological age in apparently healthy individuals.

Glucose metabolism marks health and disease and is causally inferred in the aging process. Ambulant continuous glucose monitoring provides 24-h glucose rhythms under daily life conditions. We aimed to describe ambulant 24-h glucose rhythms measured under daily life condition in relation to calendar and biological age in apparently healthy individuals. In the general population and families with propensity for longevity, we studied parameters from 24-h glucose rhythms; glucose levels; and its variability, obtained by continuous glucose monitoring. Participants were 21 young (aged 22-37 years), 37 middle-aged (aged 44-72 years) individuals from the general population, and 26 middle-aged (aged 52-74 years) individuals with propensity for longevity. All were free of diabetes. Compared with young individuals, middle-aged individuals from the general population had higher mean glucose levels (5.3 vs. 4.7 mmol L(-1) , P < 0.001), both diurnally (P < 0.001) and nocturnally (P = 0.002). Glucose variability was higher in the middle-aged compared with the young (standard deviation 0.70 vs. 0.57 mmol L(-1) , P = 0.025). Compared with middle-aged individuals from the general population, middle-aged individuals with propensity for longevity had lower overall mean glucose levels (5.2 vs. 5.4 mmol L(-1) , P = 0.047), which were more different nocturnally (4.8 vs. 5.2 mmol L(-1) , P = 0.003) than diurnally (5.3 vs. 5.5 mmol L(-1) , P = 0.14). There were no differences in glucose variability between these groups. Results were independent of body mass index. Among individuals without diabetes, we observed significantly different 24-h glucose rhythms depending on calendar and biological age.

Responsiveness of the innate immune system and glucose concentrations in the oldest old.

Patients with diabetes mellitus show increased risk of infectious disease as well as disturbances in innate immunity. In critical care settings, hyperglycemia is associated with increased risk of sepsis. It is unclear whether elevated glucose concentrations and innate immunity are associated in a non-clinical setting. We aimed to assess the association between glucose concentrations and innate immune response in the oldest old, who are at increased risk of both disturbed glucose metabolism as well as infectious disease. This study was part of the Leiden 85-plus Study. In 562 subjects aged 85 years old of the general population, venous blood samples were taken for measurement of morning glucose, C-reactive protein (CRP) and glycated hemoglobin (HbA1c). The innate immune response was assessed by performing ex vivo whole blood lipopolysaccharide (LPS) stimulation for production capacity of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1-beta (IL1-ß), interleukin 10 (IL-10) and interleukin 1 receptor antagonist (IL-1Ra). Using linear regression analysis, cross-sectional analysis between glucose and cytokine production capacity was performed. We found a significant negative association between glucose concentrations, but not HbA1c, and cytokine response capacity in four out of five measured cytokines (all p < 0.05). Both glucose and HbA1c were positively associated with circulating levels of CRP. Higher glucose concentrations in non-diabetic elderly are associated with lower innate immune response. As elderly show increased vulnerability for disturbances in glucose metabolism as well as infectious disease, this relation could be of clinical significance.

Serum triiodothyronine levels and inflammatory cytokine production capacity.

Increasing evidence suggests that pro-inflammatory cytokines are at play in lowering peripheral thyroid hormone levels during critical illness. Conversely, thyroid hormones have been suggested to enhance production of inflammatory cytokines. In view of these considerations, we hypothesized a mutual association between triiodothyronine and pro-inflammatory cytokines. Therefore we evaluated the relation between both circulating and induced inflammatory markers and serum thyroid function parameters in the Leiden 85-plus Study. We found that higher circulating levels of inflammatory markers were associated with lower levels of free serum triiodothyronine. In turn, higher serum free triiodothyronine levels were related to higher production capacity of pro-inflammatory cytokines after stimulation with lipopolysaccharide. By combining in vivo and ex vivo data, we were able to demonstrate for the first time the existence of a potential feedback mechanism between thyroid function and immune production capacity. We conclude that maintenance of normal thyroid function might be important for a preserved immune response in elderly human populations.

An unopposed proinflammatory response is beneficial for survival in the oldest old. Results of the Leiden 85-plus Study.

The capacity to generate an efficient innate immune response is pivotal for survival. The objective of this study was to investigate innate immune function in relation to long-term survival in the oldest old. We measured ex vivo lipopolysaccharide-induced proinflammatory and antiinflammatory cytokine responses in 562 participants aged 85 years of the general population who were followed for mortality during 10 years. Compared with participants with a high proinflammatory and antiinflammatory response profile, 85 year olds with an overall low proinflammatory and antiinflammatory response had a significant higher mortality risk (hazard ratio: 1.79, 95% confidence interval: 1.29-2.50), whereas participants with a high proinflammatory and low antiinflammatory response had a survival benefit (hazard ratio: 0.74, 95% confidence interval: 0.57-0.97). This benefit was even more pronounced in survivors past 90 years of age (hazard ratio: 0.50, 95% confidence interval: 0.26-0.96). In old age, the capacity to generate an unopposed proinflammatory innate immune response is predictive of long-term survival.

C-reactive protein and glucose regulation in familial longevity.

Earlier, we showed that the offspring from exceptionally long-lived families have a more favorable glucose metabolism when compared with controls. As chronic low-grade inflammation has been regarded as a strong risk factor for insulin resistance, we evaluated if and to what extent the favorable glucose metabolism in offspring from long-lived families could be explained by differences in subclinical inflammation, as estimated from circulating levels of C-reactive protein. We found no difference between the two groups in C-reactive protein levels or in the distribution of C-reactive protein haplotypes. However, among controls higher levels of C-reactive protein were related to higher glucose levels, whereas among offspring levels of C-reactive protein were unrelated to glucose levels. It is a limitation of the current study that its cross-sectional nature does not allow for assessment of cause-effect relationships. One possible interpretation of these data is that the offspring from long-lived families might be able to regulate glucose levels more tightly under conditions of low-grade inflammation. To test this hypothesis, our future research will be focused on assessing the robustness of insulin sensitivity in response to various challenges in offspring from long-lived families and controls.

Familial longevity is marked by enhanced insulin sensitivity.

Insulin resistance is a risk factor for various age-related diseases. In the Leiden Longevity study, we recruited long-lived siblings and their offspring. Previously, we showed that, compared to controls, the offspring of long-lived siblings had a better glucose tolerance. Here, we compared groups of offspring from long-lived siblings and controls for the relation between insulin and glucose in nonfasted serum (n = 1848 subjects) and for quantitation of insulin action using a two-step hyperinsulinemic-euglycemic clamp (n = 24 subjects). Groups of offspring and controls were similar with regard to sex distribution, age, and body mass index. We observed a positive bi-phasic linear relationship between ln (insulin) levels and nonfasted glucose with a steeper slope from 10.7mU L(-1) insulin onwards in controls compared to offspring (P = 0.02). During the clamp study, higher glucose infusion rate was required to maintain euglycemia during high-dose insulin infusion (P = 0.036) in offspring, reflecting higher whole-body insulin sensitivity. After adjustment for sex, age, and fat mass, the insulin-mediated glucose disposal rate (GDR) was higher in offspring than controls (42.5 ± 2.7 vs. 33.2 ± 2.7 micromol kg(-1) min(-1) , mean ± SE, P = 0.025). The insulin-mediated suppression of endogenous glucose production and lipolysis did not differ between groups (all P > 0.05). Furthermore, GDR was significantly correlated with the mean age of death of the parents. In conclusion, offspring from long-lived siblings are marked by enhanced peripheral glucose disposal. Future research will focus on identifying the underlying biomolecular mechanisms, with the aim to promote health in old age.

Homocysteine and familial longevity: the Leiden Longevity Study.

Homocysteine concentrations are a read-out of methionine metabolism and have been related to changes in lifespan in animal models. In humans, high homocysteine concentrations are an important predictor of age related disease. We aimed to explore the association of homocysteine with familial longevity by testing whether homocysteine is lower in individuals that are genetically enriched for longevity. We measured concentrations of total homocysteine in 1907 subjects from the Leiden Longevity Study consisting of 1309 offspring of nonagenarian siblings, who are enriched with familial factors promoting longevity, and 598 partners thereof as population controls. We found that homocysteine was related to age, creatinine, folate, vitamin B levels and medical history of hypertension and stroke in both groups (all p<0.001). However, levels of homocysteine did not differ between offspring enriched for longevity and their partners, and no differences in the age-related rise in homocysteine levels were found between groups (p for interaction 0.63). The results suggest that homocysteine metabolism is not likely to predict familial longevity.

Polymorphisms associated with type 2 diabetes in familial longevity: The Leiden Longevity Study.

Human longevity is in part genetically determined, and the insulin/IGF-1 signal transduction (IIS) pathway has consistently been implicated. In humans, type 2 diabetes is a frequent disease that results from loss of glucose homeostasis and for which new candidate polymorphisms now rapidly emerge from genome wide association studies. In the Leiden Longevity Study (n=2415), the offspring of long lived siblings ("offspring") who are genetically enriched for longevity were shown to have a more beneficial metabolic profile compared to their environmentally matched partners ("controls"), including better glucose tolerance. We tested whether the "offspring" carry a lower burden of diabetes risk alleles. Fifteen polymorphisms derived from genome wide association (GWA) scans in type 2 diabetes were tested for association with parameters of glucose metabolism in offspring and controls, and burden of risk alleles was compared between offspring and controls. Among all participants, a higher number of type 2 diabetes risk alleles associated with a higher prevalence of diabetes (P=0.011) and higher serum concentration of glucose (P<0.016) but not insulin (P=0.450). None of the polymorphisms differed in frequency between the offspring and controls (all P>0.05), nor did the mean total number of risk alleles (P=0.977). The association between polymorphisms and glucose levels did not differ between controls and offspring (Pinteraction=0.523). The better glucose tolerance of the "offspring" is not explained by a lower burden of type 2 diabetes risk alleles, suggesting that specific mechanisms determining longevity exist.

Favorable glucose tolerance and lower prevalence of metabolic syndrome in offspring without diabetes mellitus of nonagenarian siblings: the Leiden longevity study.

OBJECTIVES: To explore measures of metabolic syndrome and glucose metabolism in families with exceptional longevity. DESIGN: Case-control study. SETTING: A university hospital in Leiden, the Netherlands. PARTICIPANTS: One hundred twenty-one offspring of nonagenarian siblings, who were enriched for familial factors promoting longevity, and 113 of their partners. No subject had diabetes mellitus. MEASUREMENTS: Prevalence of metabolic syndrome was determined according to the criteria of the Third Report of the National Cholesterol Education Program. Glucose tolerance was assessed according to a 2-hour oral glucose tolerance test. RESULTS: The offspring of nonagenarians siblings had a lower prevalence of metabolic syndrome (P=.03), similar body composition, lower mean fasting blood glucose levels (4.99 vs 5.16 mmol/L; P=.01), lower mean fasting insulin levels (5.81 vs 6.75 mU/L; P=.04), a higher mean homeostasis model assessment of insulin sensitivity (0.78 vs 0.65; P=.02), and a more-favorable glucose tolerance (mean area under the receiver operating characteristic curve for glucose (13.2 vs 14.3; P=.007) than their partners. No significant differences were observed between the offspring and their partners in beta-cell function (insulogenic index 13.6 vs 12.5; P=.38). CONCLUSION: Despite similar body composition, the offspring of nonagenarian siblings showed a lower prevalence of metabolic syndrome and better glucose tolerance than their partners, centralizing the role of favorable glucose metabolism in familial longevity.