Secondary hyperparathyroidism: Predictors and relationship with vitamin D status, bone turnover markers and bone mineral density.

INTRODUCTION: Secondary hyperparathyroidism (SHPT) has adverse implications for bone health but is relatively understudied. In this study we examine the prevalence and determinants of SHPT and describe the relationship of SHPT with bone turnover markers and bone mineral density (BMD) in older Irish adults. METHOD: Eligible participants (n = 4139) were identified from the Trinity-Ulster-Department of Agriculture (TUDA) study, a cohort of Irish adults aged ≥60 years. Exclusion criteria included an estimated glomerular filtration rate (eGFR) <30 ml/min and serum calcium >2.5 mmol/l to remove hyperparathyroidism due to advanced chronic kidney disease (CKD) and primary hyperparathyroidism respectively. The relationship between SHPT and bone turnover markers and BMD (measured by densitometry) was examined in a subsample (n = 1488). Vitamin D deficiency was defined as 25-hydroxyvitamin D [25 (OH)D] <30 nmol/l. RESULTS: Participants had a mean age of 73.6 ± 7.9 years, 65.1 % were female and 19.4 % were found to be vitamin D deficient. The prevalence of SHPT decreased as vitamin D increased, from 30.6 % in those deficient to 9.8 % in those with 25(OH)D ≥ 50 nmol/l and increased with declining kidney function. In non­calcium supplement users, principal determinants of SHPT were vitamin D deficiency (OR 4.18, CI 3.05-5.73, p < 0.001), eGFR 30-44 ml/min (OR 3.69, CI 2.44-5.57, p < 0.001), loop diuretic use (OR 3.52, CI 2.59-4.79, p < 0.001) and to a lesser extent body mass index (p = 0.001), eGFR 45-59 ml/min (p < 0.001) and 25(OH)D level 30-49 nmol/l (p = 0.002). Similar findings were observed in calcium supplement users, though proton pump inhibitors were also associated with SHPT (OR 1.55, CI 1.08-2.22, p = 0.018) while vitamin D 30-49 nmol/l was not. In participants with SHPT versus those without, bone turnover markers were higher: bone alkaline phosphatase (p = 0.017) and tartrate-resistant acid phosphatase (p = 0.033), whilst there was lower BMD at the neck of femur (0.880 vs. 0.903 g/cm2, p = 0.033) and total hip (0.968 vs. 0.995 g/cm2, P = 0.017). DISCUSSION: The results show that up to one in six older Irish adults had SHPT and this was associated with lower BMD and higher concentrations of bone turnover markers. Both vitamin D deficiency and 25(OH)D level 30-49 nmol/l were important predictors of SHPT. Loop diuretics and PPIs may also increase the risk of SHPT, and their use may need to be carefully considered in this population. Further studies examining the potential impact of these factors on bone health in similar populations to our study sample are warranted.

Low-Grade systemic inflammation is associated with domain-specific cognitive performance and cognitive decline in older adults: Data from the TUDA study.

Studies examining the relationships between chronic inflammation, cognitive function and cognitive decline in older adults have yielded conflicting results. In a large cohort of older adults free from established dementia (n = 3270; 73.1 ± 7.9 years; 68.4% female), we evaluated the cross-sectional and longitudinal relationships between serum cytokines (IL-6, IL-10, TNF-α) and both global and domain-specific cognitive performance (Repeatable Battery for Assessment of Neuropsychological Status [RBANS]). Higher IL-6 (OR: 1.33; 1.06, 1.66, p = 0.01), TNF-α (OR: 1.35; 1.09, 1.67, p = 0.01) and IL-6:IL-10 Ratio (OR: 1.43; 1.17, 1.74, p = 0.001) were cross-sectionally associated with impaired global RBANS performance. For specific cognitive domains, greatest effect sizes were observed between higher TNF-α levels and poorer visual-spatial and attention performance. In a subset of participants (n = 725; 69.8 ± 5.5 years; 67.0% female) with repeat assessment performed at a median of 5.4 years, only higher baseline IL-6:IL-10 ratio was associated with impaired incident overall, immediate memory and visual-spatial performance. Associations were stronger in females, but not modified by age or APOE genotype.

Dietary selenium and mercury intakes from fish consumption during pregnancy: Seychelles Child Development Study Nutrition Cohort 2.

Some health agencies have issued precautionary principle fish advisories to pregnant women based on the presence of methylmercury (MeHg) in fish that could possibly be harmful to the developing fetus. Fish, however, is a rich source of selenium (Se) and other nutrients essential for normal brain development. Selenium is also thought to have a key role in alleviating MeHg toxicity. We estimated the dietary Se and MeHg intakes and dietary Se:Hg molar ratios from the fish consumed in a high fish-eating pregnant cohort where no adverse associations of fish consumption and outcomes has been reported. We used dietary data collected as part of the Seychelles Child Development Study Nutrition Cohort 2 (n = 1419). In this cohort 98% of participants consumed fish, with an average intake of 106.2 g per day. Daily Se intakes from fish consumption were 61.6 µg/ d, within the range recommended during pregnancy. The mean dietary Se:Hg molar ratios was 6. These findings demonstrate that fish consumption exposes pregnant Seychellois women to Se in excess of MeHg. Based on these findings, fish consumption, especially fish with Se:Hg ratios above 1, may help pregnant women achieve optimum dietary Se intakes, which may protect against MeHg toxicity.

Postnatal methylmercury exposure and neurodevelopmental outcomes at 7 years of age in the Seychelles Child Development Study Nutrition Cohort 2.

BACKGROUND: Consumption of fish yields many nutritional benefits, but also results in exposure to methylmercury (MeHg). The developing brain is known to be particularly susceptible to MeHg toxicity in high doses. However, the potential impact of low-level environmental exposure from fish consumption on children's neurodevelopment remains unclear. METHODS: We investigated postnatal MeHg exposure at 7 years and its association with a battery of 17 neurodevelopmental outcomes in a subset of children (n = 376) from 1535 enrolled mother-child pairs in Nutrition Cohort 2 of the Seychelles Child Development Study (SCDS NC2). Each outcome was modeled in relation to postnatal MeHg exposure using linear regression, adjusting for prenatal MeHg exposure, levels of maternal polyunsaturated fatty acids (PUFA), and several other covariates known to be associated with neurodevelopmental outcomes. RESULTS: Median postnatal MeHg exposure at 7 years was 2.5 ppm, while the median prenatal MeHg exposure was 3.5 ppm. We found no statistically significant associations between postnatal MeHg exposure and any of the 17 neurodevelopmental outcomes after adjusting for prenatal MeHg exposure and other covariates. CONCLUSIONS: These findings are consistent with previous cross-sectional analyses of the SCDS Main Cohort. Continued follow-up of the entire NC2 cohort at later ages with repeated exposure measures is needed to further confirm these findings.

Net effects explains the benefits to children from maternal fish consumption despite methylmercury in fish.

In 2001 the U.S. Food and Drug Administration (FDA) issued precautionary advice to pregnant women to limit fish consumption over concern that the methylmercury content might harm their children's neurodevelopment. This concern was based largely on results from an epidemiological study of mothers primarily exposed to methylmercury from consuming pilot whale. Subsequently, FDA and the World Health Organization/Food and Agriculture Organization (WHO/FAO) undertook independent assessments of fish consumption that considered net effects from both fish nutrients, primarily omega-3 fatty acids, as beneficial and methylmercury as harmful. Both assessments estimated that when mothers regularly consume fish during pregnancy, their children are likely to have improved neurodevelopment compared to children of non-fish eaters despite their exposure to methylmercury. These estimated improvements included gains of two to over five full scale IQ points from levels of maternal consumption that are achievable in most of the world. Consistent with those estimates, human research on fish consumption and child neurodevelopment from more than 200,000 mother-child pairs now collectively reports 51 beneficial associations with neurodevelopmental outcomes and three adverse associations, the latter with no discernable pattern. These associations include full scale IQ gains similar to, or somewhat higher than, those estimated by FDA and FAO/WHO. Also consistent with the FDA and FAO/WHO estimates, research has reported beneficial associations with fish consumption when pregnant women are exposed to methylmercury from fish in excess of the U.S. Environmental Protection Agency's (EPA) Reference Dose (RfD). Our analysis evaluates how the net effects approach as utilized by FDA and FAO/WHO provides a holistic explanation for these results with implications for public health policy. This concordance of net effects modeling and empirical scientific evidence supports a clarification of current public health recommendations to focus on greater fish consumption by pregnant women for their children's neurodevelopment.

KEAP1 polymorphisms and neurodevelopmental outcomes in children with exposure to prenatal MeHg from the Seychelles Child Development Study Nutrition Cohort 2.

BACKGROUND: Humans differ in the metabolism of the neurotoxicant methyl mercury (MeHg). This variation may be partially due to variation in genes encoding the transcription factor Nuclear factor E2-related factor 2 (NRF2) and its negative regulator Kelch-like ECH-Associated Protein 1 (KEAP1), which regulate glutathione and related transporter and antioxidant proteins that play a role in the metabolism and neurotoxicity of MeHg. AIM: To elucidate a potential risk from genetic variation in NFE2L2 (encoding NRF2) and KEAP1 toward prenatal mercury exposure and child neurodevelopmental outcomes at 20 months and 7 years of age in a population with variable prenatal exposure to MeHg from maternal fish consumption. MATERIAL AND METHODS: Nutrition Cohort 2 is a mother-child cohort in the Republic of Seychelles. Children were genotyped for NFE2L2 (rs2364723, rs13001694) and KEAP1 (rs8113472, rs9676881) polymorphisms (N = 1285 after removing siblings). Total mercury (Hg) was measured in cord blood as a biomarker for prenatal MeHg exposure. Child neurodevelopmental outcomes included the Bayley Scales of Infant Development II administered at 20 months of age, and outcomes across multiple neurodevelopmental domains from 14 tests administered in children and 3 instruments completed by parents when children were 7 years of age. RESULTS: The mean cord blood MeHg concentration was 34 (95% CI 11, 75) µg/L. None of the four polymorphisms had a significant association (p < 0.05) with either cord MeHg or neurodevelopmental test results at 20 months. There were no significant associations between either NFE2L2 polymorphism and any developmental test scores. At 7 years, children carrying KEAP1 rs8113472 CA showed significantly worse performance on psychomotor function than children with the CC variant (finger tapping, dominant hand: ß - 1.19, SE 0.34; finger tapping, non-dominant hand: ß - 0.92, SE 0.31) and worse social communication (SCQ Total: ß 0.65, SE 0.27). Children carrying rs8113472 AA, versus children with CC, showed significantly better performance on social communication (SRS Total: ß - 8.88, SE 3.60). Children carrying KEAP1 rs9676881 AG, versus children with GG, showed significantly worse performance on psychomotor function (trailmaking A time: ß 8.66, SE 3.37) and cognition (KBIT Matrices: ß - 0.96, SE 0.36). CONCLUSION: No associations between NFE2L2 and KEAP1 polymorphisms and MeHg concentration were identified. However, at 7 years, KEAP1 polymorphisms were associated with differences in neurodevelopmental outcomes in children from a population with high fish intake.

Fish consumption and its lipid modifying effects - A review of intervention studies.

Fish is an important source of nutrients, particularly the long chain n-3 polyunsaturated fatty acids (n-3 PUFAs). The incorporation of fish into the diet has been shown to have several health benefits, including lowering the risk of cardiovascular disease (CVD). Elevated plasma lipids are one of the main modifiable risk factors contributing to CVD and may be partly mediated by n-3 PUFAs. Although n-3 PUFAs in the form of supplementation have been shown to exert lipid modifying effects, the effects of fish consumption on the lipid profile have not been well summarised to date. Therefore, the aim of the present review is to discuss the current evidence from intervention studies investigating the effect of fish consumption on the lipid profile in both apparently healthy and non-healthy populations. Existing evidence appears to support the role of fish in promoting a shift towards a less inflammatory lipid profile through raising n-3 PUFAs and potentially lowering n-6 PUFA and triglyceride concentrations in both healthy and non-healthy populations. Fish consumption has a negligible effect on cholesterol concentrations; however, fish consumption may promote a small increase in high density lipoprotein (HDL) cholesterol amongst people with lower HDL at baseline. Limited studies have shown fish consumption to result in shifts in phospholipid and sphingolipid species and structure, albeit it is not yet clear whether these alterations have any meaningful impact on CVD risk. Future well-designed studies that utilise NMR and/or lipidomics analysis are warranted to explore the effects of these shifts in lipid content and structure in the context of disease development. Public health guidance should emphasise the cardioprotective benefits of fish and encourage consumption particularly in the Global North where fish consumption remains low.

Potential role of selenium in modifying the effect of maternal methylmercury exposure on child neurodevelopment - A review.

Selenium (Se) is an essential trace element for normal neurodevelopment. It is incorporated into multiple selenoenzymes which have roles in the brain and neurological function, the synthesis of thyroid hormones, the antioxidant defense system, DNA synthesis, and reproduction. Fish is a source of both Se and neurotoxic methylmercury (MeHg). Selenium is known to ameliorate the effects of MeHg in experimental animals, but studies in children exposed to both Se and MeHg through prenatal fish consumption have been inconclusive. Research on Se's implications for pregnancy and child neurodevelopment is limited. The aims of this review are to summarize the literature on the biological roles of Se during pregnancy and the potential role in mitigating the effects of MeHg exposure from fish consumption on human health. This review has shown that Se concentrations among pregnant women globally appear insufficient, with the majority of pregnant women reporting Se concentrations below 70 µg/L during pregnancy. The role of Se in child development and its interactions with MeHg in children are inconclusive. Further investigation of the interaction between Se and MeHg in relation to child neurodevelopment in high fish-eating populations is required to fully elucidate effects.

The association between proton pump inhibitors and hyperparathyroidism: a potential mechanism for increased fracture-results of a large observational cohort study.

Proton pump inhibitors (PPIs) are associated with increased risk of osteoporotic fracture; however, the mechanism is unclear. PPI users taking calcium supplements were more likely to have hyperparathyroidism compared to non-users (OR 1.56, CI 1.08-2.23, p = 0.018). This highlights the importance of monitoring PPI use, especially in older adults. PURPOSE: Proton pump inhibitors (PPIs) are associated with increased risk of osteoporotic fracture. Hyperparathyroidism may be implicated, but few studies have considered this relationship. This study evaluated the relationship between PPI use and hyperparathyroidism in older adults. METHODS: Participants were from the TUDA study, a large cross-sectional cohort of older Irish adults. Participants with an estimated glomerular filtration rate (eGFR) < 30 ml/min and serum calcium > 2.5 mmol/l were excluded to avoid hyperparathyroidism due to chronic renal disease and primary hyperparathyroidism. Hyperparathyroidism was defined as a parathyroid hormone (PTH) > 65 pg/ml. Multivariate regression models were used to analyse the relationship between PPI use and hyperparathyroidism. RESULTS: A total of 4139 participants met the inclusion criteria, of whom 37.8% (n = 1563) were taking PPI medication. PPI use was identified in 41.4% of calcium supplement users and 35.4% of non-calcium supplement users. Overall, compared to non-users of PPIs, those taking PPIs were older (74.8 vs 72.9 years, p < 0.001) and had a higher prevalence of hyperparathyroidism (17.8 vs 11.0%, p < 0.001). In those taking calcium supplements (but not in non-users), PPI use was significantly associated with hyperparathyroidism (OR 1.56, CI 1.08-2.23, p = 0.018) after adjusting for age, sex, body mass index, serum vitamin D, eGFR, timed-up-and-go, dairy intake, medications, and comorbidities. DISCUSSION: The results are consistent with the hypothesis of PPIs reducing calcium absorption, leading to a rise in PTH which could mediate increased fracture risk. No relationship of PPI use with hyperparathyroidism was observed in non-users of calcium supplements, possibly owing to lower dietary calcium intake. These results highlight the importance of monitoring PPI use, especially in older adults at risk of fracture.

Associations between serum taurine concentrations in mothers and neonates and the children's anthropometrics and early neurodevelopment: Results from the Seychelles Child Development Study, Nutrition Cohort 2.

BACKGROUND: High concentrations of taurine are present in the developing human brain and maternal breast milk. Taurine is thought to influence fetal growth and brain development based on experimental rodent studies. As fish is an important dietary source of taurine, we investigated associations between taurine concentrations and child outcomes in a high fish consuming population. OBJECTIVE: To examine associations between maternal and cord serum taurine concentrations and birth anthropometric measures and cognitive development in children at 20 months of age. METHODS: Pregnant women were recruited between 2008 and 2011 as part of Nutrition Cohort 2 (NC2) of the Seychelles Child Development Study (SCDS). Maternal taurine serum concentrations were measured at 28 week's gestation and in cord serum. Child weight, length and head circumference were measured at birth and neurodevelopment was assessed using Bayley Scales of Infant Development II (BSID-II) at 20 months of age. Associations between taurine status, birth measures and neurodevelopmental outcomes were examined (n = 300) using regression models and adjusted for relevant covariates. RESULTS: Mean (SD) maternal and cord taurine concentrations were 124.9 (39.2) µmol/L (range 28.2-253.9 µmol/L) and 187.6 (60.0) µmol/L (range 55.0-417.4 µmol/L) respectively. We found no associations between maternal taurine concentrations and child anthropometric and neurodevelopmental measures (weight ß = -0.001, SE=0.001; length ß = -0.006, SE=0.006; head circumference ß = -0.002, SE=0.002; MDI ß = -0.005, SE=0.015; PDI ß = -0.004, SE=0.016; all P > 0.05), or between cord taurine concentrations and outcomes (weight ß = -0.001, SE<0.000; length ß = -0.001, SE=0.004; head circumference ß < 0.000, SE=0.002; MDI ß = 0.004, SE=0.010; PDI ß = -0.015, SE=0.012; all P > 0.05). CONCLUSION: The Seychellois population have high maternal and cord taurine concentrations owing to their high fish intake and may be considered taurine replete compared to individuals who consume a Westernised diet. This high taurine status may explain why there were no significant associations between maternal and cord taurine concentrations and outcomes after adjusting for covariates.

Association of dietary flavan-3-ol intakes with plasma phenyl-γ-valerolactones: analysis from the TUDA cohort of healthy older adults.

BACKGROUND: Dietary polyphenols, including flavan-3-ols (F3O), are associated with better health outcomes. The relationship of plasma phenyl-γ-valerolactones (PVLs), the products of colonic bacterial metabolism of F3O, with dietary intakes is unclear. OBJECTIVES: To investigate whether plasma PVLs are associated with self-reported intakes of total F3O and procyanidins+(epi)catechins. DESIGN: We measured 9 PVLs by uHPLC-MS-MS in plasma from adults (>60y) in the Trinity-Ulster-Department of Agriculture (TUDA study (2008 to 2012; n=5186) and a follow-up subset (2014 to 2018) with corresponding dietary data (n=557). Dietary (poly)phenols collected by FFQ were analyzed using Phenol-Explorer. RESULTS: Mean (95% confidence interval [CI]) intakes were estimated as 2283 (2213, 2352) mg/d for total (poly)phenols, 674 (648, 701) for total F3O, and 152 (146, 158) for procyanidins+(epi)catechins. Two PVL metabolites were detected in plasma from the majority of participants, 5-(hydroxyphenyl)-γ-VL-sulfate (PVL1) and 5-(4'-hydroxyphenyl)-γ-VL-3'-glucuronide (PVL2). The 7 other PVLs were detectable only in 1-32% of samples. Self-reported intakes (mg/d) of F3O (r = 0.113, P = 0.017) and procyanidin+(epi)catechin (r = 0.122, P = 0.010) showed statistically significant correlations with the sum of PVL1 and PVL 2 (PVL1+2). With increasing intake quartiles (Q1-Q4), mean (95% CI) PVL1+2 increased; from 28.3 (20.8, 35.9) nmol/L in Q1 to 45.2 (37.2, 53.2) nmol/L in Q4; P = 0.025, for dietary F3O, and from 27.4 (19.1, 35.8) nmol/L in Q1 to 46.5 (38.2, 54.9) nmol/L in Q4; P = 0.020, for procyanidins+(epi)catechins. CONCLUSIONS: Of 9 PVL metabolites investigated, 2 were detected in most samples and were weakly associated with intakes of total F3O and procyanidins+(epi)catechins. Future controlled feeding studies are required to validate plasma PVLs as biomarkers of these dietary polyphenols.

Maternal fish consumption and child neurodevelopment in Nutrition 1 Cohort: Seychelles Child Development Study.

Maternal fish consumption exposes the fetus to beneficial nutrients and potentially adverse neurotoxicants. The current study investigated associations between maternal fish consumption and child neurodevelopmental outcomes. Maternal fish consumption was assessed in the Seychelles Child Development Study Nutrition Cohort 1 (n 229) using 4-day food diaries. Neurodevelopment was evaluated at 9 and 30 months, and 5 and 9 years with test batteries assessing twenty-six endpoints and covering multiple neurodevelopmental domains. Analyses used multiple linear regression with adjustment for covariates known to influence child neurodevelopment. This cohort consumed an average of 8 fish meals/week and the total fish intake during pregnancy was 106·8 (sd 61·9) g/d. Among the twenty-six endpoints evaluated in the primary analysis there was one beneficial association. Children whose mothers consumed larger quantities of fish performed marginally better on the Kaufman Brief Intelligence Test (a test of nonverbal intelligence) at age 5 years (ß 0·003, 95 % CI (0, 0·005)). A secondary analysis dividing fish consumption into tertiles found no significant associations when comparing the highest and lowest consumption groups. In this cohort, where fish consumption is substantially higher than current global recommendations, maternal fish consumption during pregnancy was not beneficially or adversely associated with children's neurodevelopmental outcomes.

Associations of long chain polyunsaturated fatty acids with bone mineral density and bone turnover in postmenopausal women.

PURPOSE: The immunomodulatory properties of n-3 long chain polyunsaturated fatty acids (LCPUFA) are reported to reduce bone loss through alteration of bone remodelling and n-3 LCPUFA, therefore, may benefit bone health in post-menopausal women, a vulnerable group at high risk of osteoporosis. METHODS: Measures of bone mineral density (BMD) were determined using dual energy X-ray absorptiometry (DEXA) in 300 post-menopausal women. The bone turnover markers osteocalcin (OC), C-terminal telopeptides of type 1 collagen (CTX) and total alkaline phosphatase were quantified in serum along with urinary creatinine corrected deoxypyridinoline (DPD/Cr) and CTX/Cr and the CTX:OC ratio calculated. Total serum n-6 PUFA (LA + AA) and n - 3 LCPUFA (ALA + EPA + DPA + DHA) were measured and the n - 6:n - 3 ratio was calculated. RESULTS: Mean (SD) age and body mass index (BMI) were 61 (6.4) years and 27.4 (4.8) kg/m2, respectively with participants being 12.6 (7.6) years post-menopause. Multiple regression analysis identified no association between n-3 LCPUFA and any of the measures of T-score or BMD albeit a significant positive association between total n - 3 LCPUFA and femur BMD (ß = 0.287; p = 0.043) was observed within those women with a low n - 6:n - 3 ratio. There was a significant inverse association between ALA and urinary DPD/Cr (ß = - 0.141; p = 0.016). CONCLUSION: A favourable low n - 6:n - 3 ratio was associated with higher femur BMD and a higher n - 3 LCPUFA (ALA) was associated with lower bone resorption. These results support a beneficial role for n - 3 LCPUFA in reducing postmenopausal bone resorption and favourably influencing BMD. TRIAL NUMBER & DATE OF REGISTRATION: ISRCTN63118444, 2nd October 2009, "Retrospectively registered".

Vitamin B-6 and riboflavin, their metabolic interaction, and relationship with MTHFR genotype in adults aged 18-102 years.

BACKGROUND: The generation of the active form of vitamin B-6, pyridoxal 5'-phosphate (PLP), in tissues is dependent upon riboflavin as flavin mononucleotide, but whether this interaction is important for maintaining vitamin B-6 status is unclear. OBJECTIVE: To investigate vitamin B-6 and riboflavin status, their metabolic interaction, and relationship with methylenetetrahydrofolate reductase (MTHFR) genotype in adulthood. METHODS: Data from 5612 adults aged 18-102 y were drawn from the Irish National Adult Nutrition Survey (NANS; population-based sample) and the Trinity-Ulster Department of Agriculture (TUDA) and Genovit cohorts (volunteer samples). Plasma PLP and erythrocyte glutathione reductase activation coefficient (EGRac), as a functional indicator of riboflavin, were determined. RESULTS: Older (≥65 y) compared with younger (<65 y) adults had significantly lower PLP concentrations (P < 0.001). A stepwise decrease in plasma PLP was observed across riboflavin categories, from optimal (EGRac ≤1.26), to suboptimal (EGRac: 1.27-1.39), to deficient (EGRac ≥1.40) status, an effect most pronounced in older adults (mean ± SEM: 76.4 ± 0.9 vs 65.0 ± 1.1 vs 55.4 ± 1.2 nmol/L; P < 0.001). In individuals with the variant MTHFR 677TT genotype combined with riboflavin deficiency, compared with non-TT (CC/CT) genotype participants with sufficient riboflavin, we observed PLP concentrations of 52.1 ± 2.9 compared with 76.8 ±0.7 nmol/L (P < 0.001). In participants with available dietary data (i.e., NANS cohort, n = 936), PLP was associated with vitamin B-6 intake (nonstandardized regression coefficient ß: 2.49; 95% CI 1.75, 3.24; P < 0.001), supplement use (ß: 81.72; 95% CI: 66.01, 97.43; P < 0.001), fortified food (ß: 12.49; 95% CI: 2.08, 22.91; P = 0.019), and EGRac (ß: -65.81; 95% CI: -99.08, -32.54; P < 0.001), along with BMI (ß: -1.81; 95% CI: -3.31, -0.30; P = 0.019). CONCLUSIONS: These results are consistent with the known metabolic dependency of PLP on flavin mononucleotide (FMN) and suggest that riboflavin may be the limiting nutrient for maintaining vitamin B-6 status, particularly in individuals with the MTHFR 677TT genotype. Randomized trials are necessary to investigate the PLP response to riboflavin intervention within the dietary range. The TUDA study and the NANS are registered at www.ClinicalTrials.gov as NCT02664584 (27 January 2016) and NCT03374748 (15 December 2017), respectively.Clinical Trial Registry details: Trinity-Ulster-Department of Agriculture (TUDA) study, ClinicalTrials.gov no. NCT02664584 (January 27th 2016); National Adult Nutrition Survey (NANS), ClinicalTrials.gov no. NCT03374748 (December 15th 2017).

A 2-Year Randomized Controlled Trial With Low-Dose B-Vitamin Supplementation Shows Benefits on Bone Mineral Density in Adults With Lower B12 Status.

Folate, vitamins B12, B6, and riboflavin are required for one-carbon metabolism and may affect bone health, but no previous randomized trial has investigated all four nutrients in this context. We investigated the effect of low-dose B-vitamins for 2 years on bone mineral density (BMD) in a dual-centered, 2-year randomized controlled trial (RCT) in adults aged ≥50 years. Eligible participants not consuming B-vitamin supplements or fortified foods >4 times weekly were randomized to receive daily either combined folic acid (200 µg), vitamin B12 (10 µg), vitamin B6 (10 mg), and riboflavin (5 mg), or "active" placebo, whereby both the intervention and placebo groups received vitamin D (10 µg). BMD was assessed before and after intervention using dual-energy X-ray absorptiometry (DXA) scanning of the total hip, femoral neck, and lumbar spine (L1 to L4). Of 205 eligible participants randomized, 167 completed the trial in full. B-vitamin intervention resulted in increases in serum folate (p < 0.001), serum B12 (p < 0.001), and plasma pyridoxal-5-phosphate (p < 0.001) and decreases in functional biomarkers of B-vitamin status, erythrocyte glutathione reductase activation coefficient (p < 0.001), serum methylmalonic acid (MMA; p < 0.001), and serum total homocysteine (p < 0.001). B-vitamin intervention had no overall effect on BMD, which declined in both treatment groups by approximately 1% (ranging from -0.7% to -1.4%). However, in participants with lower baseline B12 status (serum B12 <246 pmol/L or MMA ≥0.22 µmol/L), B-vitamin intervention reduced the 2-year BMD decline versus placebo: adjusted mean (95% confidence interval [CI]) change of -0.003 (-0.008, 0.002) versus -0.015 (-0.021, -0.010) g/cm2 at the total hip and -0.004 (-0.010, 0.001) versus -0.013 (-0.018, -0.007) g/cm2 at the femoral neck. In conclusion, the findings indicate that although low-dose B-vitamin intervention for 2 years had no overall effect on BMD, improving B-vitamin status appears to have specific benefits for bone health in adults with lower B12 status. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Cost-effectiveness of vitamin D3 supplementation in older adults with vitamin D deficiency in Ireland.

Background: This study investigated the cost-effectiveness of vitamin D3 supplementation in older adults in Ireland, with year-round vitamin D deficiency (serum 25-hydroxyvitamin D concentration <30 nmol/L) (13% of Irish adults), from the perspective of the Health Service Executive. Methods: Three age groups were investigated: (1) ≥50 years, (2) ≥60 years and (3) ≥70 years. Based on the clinical literature, vitamin D3 supplementation may: (1) decrease all-cause mortality by 7% and (2) reduce hip fractures by 16% and non-hip fractures by 20%. A discount rate of 4% was applied to life years and quality-adjusted life years (QALYs) gained, and healthcare costs. The annual healthcare costs per patient used in the model are based on the average annual health resource use over the 5-year time horizon of the model. Results: The cost/QALY estimates in all three age groups are below the usually acceptable cost-effectiveness threshold of €20 000/QALY. The most cost-effective and least costly intervention was in adults ≥70 years. For this age group, the average annual costs and outcomes would be approximately €5.6 million, 1044 QALYs gained, with a cost/QALY of approximately €5400. The results are most sensitive to the mortality risk reduction following vitamin D3 supplementation. Conclusion: The cost-effectiveness of vitamin D3 supplementation is most robust in adults ≥70 years. Clinical uncertainty in the magnitude of the benefits of vitamin D3 supplementation could be further addressed by means of: (1) performing a clinical research study or (2) conducting a pilot/regional study, prior to reaching a decision to invest in a nationwide programme.

Vitamin D and Bone Health of Older Adults within Care Homes: An Observational Study.

Limited studies have reported vitamin D status and health outcomes in care home residents, a group at risk of vitamin D deficiency. This study investigated serum 25-hydroxyvitamin D (25-OHD) concentrations in older adults within care homes in Northern Ireland (NI) and its association with musculoskeletal health (ultrasound T-score, muscle strength, Timed Up & Go test (TUG)), bone turnover markers (BTMs), and immune function markers. A total of 87 participants were recruited with mean ± SD age 83.2 ± 7.9 years. Mean ± SD serum 25-OHD concentration (n 69) was 49.52 ± 35.58 nmol/L. Vitamin D deficiency (25-OHD <25 nmol/L) was observed in 34.8% (n 24) of participants with 17.4% (n 12) classified as insufficient (25-OHD 25−50 nmol/L) and 47.8% (n 33) as sufficient (25-OHD >50 nmol/L). 25-OHD concentration was not an independent predictor of T-score, muscle strength, TUG, or inflammatory cytokines. After adjusting for covariates, a significant negative association was observed between 25-OHD concentration and the BTMs; osteocalcin (ß = −0.395; p = 0.001), procollagen type 1 N propeptide (P1NP) (ß = −0.320; p = 0.012), and C-terminal telopeptide of type 1 collagen (CTX) (ß = −0.377; p = 0.003). Higher 25-OHD concentration was positively associated with use of vitamin D ± calcium supplementation (ß = 0.610; p < 0.001). Vitamin D deficiency and insufficiency were highly prevalent in this sample of care home residents in NI. Higher 25-OHD concentration was associated with greater supplement use and with reduced bone turnover, which in this population is linked with reduced bone loss. These findings emphasize the need for a mandatory vitamin D ± calcium supplementation policy specific for care home residents.

Impact of the MTHFR C677T polymorphism on blood pressure and related central haemodynamic parameters in healthy adults.

BACKGROUND: The C677T polymorphism in the gene-encoding methylenetetrahydrofolate reductase (MTHFR) is associated with an increased risk of hypertension and cardiovascular disease. Riboflavin, the MTHFR cofactor, is an important modulator of blood pressure (BP) in adults homozygous for this polymorphism (TT genotype). The effect of this genetic variant on BP and related central haemodynamic parameters in healthy adults has not been previously investigated and was examined in this study. METHODS: Brachial BP, central BP and pulse wave velocity (PWV, SphygmoCor XCEL) were measured in adults aged 18-65 years prescreened for MTHFR genotype. Riboflavin status was assessed using the erythrocyte glutathione reductase activation coefficient assay. RESULTS: Two hundred and forty-two adults with the MTHFR 677TT genotype and age-matched non-TT (CC/CT) genotype controls were identified from a total cohort of 2546 adults prescreened for MTHFR genotype. The TT genotype was found to be an independent determinant of hypertension (p = 0.010), along with low-riboflavin status (p = 0.002). Brachial systolic and diastolic BP were higher in TT versus non-TT adults by 5.5 ± 1.2 and 2.4 ± 0.9 mmHg, respectively (both p < 0.001). A stronger phenotype was observed in women, with an almost 10 mmHg difference in mean systolic BP in TT versus non-TT genotype groups: 134.9 (95% confidence interval [CI] 132.1-137.6) versus 125.2 (95% CI 122.3-128.0) mmHg; p < 0.001. In addition, PWV was faster in women with the TT genotype (p = 0.043). CONCLUSION: This study provides the first evidence that brachial and central BP are significantly higher in adults with the variant MTHFR 677TT genotype and that the BP phenotype is more pronounced in women.

Reduced kidney function is associated with poorer domain-specific cognitive performance in community-dwelling older adults.

OBJECTIVES: Whilst chronic kidney disease has been associated with cognitive impairment, the association between reduced estimated Glomerular Filtration Rate (eGFR) and domain-specific cognitive performance is less clear and may represent an important target for the promotion of optimal brain health in older adults. METHODS: Participants aged >60 years from the Trinity-Ulster-Department of Agriculture study underwent detailed cognitive assessment using the Mini-Mental State Examination (Mini-Mental State Examination (MMSE)), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS). Poisson and linear regression models assessed the relationship between eGFR strata and cognitive performance. RESULTS: In 4887 older adults (73.9 ± 8.3 years; 67.7% female), declining eGFR strata was associated with greater likelihood of error on the MMSE/FAB and poorer overall performance on the RBANS. Following robust covariate adjustment, findings were greatest for GFR <45 ml/ml/1.73 m2 (Incidence Rate Ratio: 1.17; 95% CI 1.08, 1.27; p < 0.001 for MMSE; IRR: 1.13; 95% CI 1.04, 1.13; p < 0.001 for FAB; ß: -3.66; 95% CI -5.64, -1.86; p < 0.001 for RBANS). Additionally, eGFR <45 ml/ml/1.73 m2 was associated with poorer performance on all five RBANS domains, with greatest effect sizes for immediate memory, delayed memory and attention. Associations were strongest in those aged 60-70, with no associations observed in those >80 years. CONCLUSIONS: Reduced kidney function was associated with poorer global and domain-specific neuropsychological performance. Associations were strongest with eGFR <45 ml/min/1.73 m2 and in those aged 60-70 years, suggesting that this population may potentially benefit from potential multi-domain interventions aimed at promoting optimal brain health in older adults.