Serum 25-hydroxyvitamin D and hypertension in premenopausal and postmenopausal women: National Health and Nutrition Examination Surveys 2007-2010

Poor vitamin D status was associated with increased appendicular fat deposition in US Adults: Data from 2011-2018 National Health and Nutrition Examination Survey

The aim of the study was to explore the relationship between serum 25-hydroxyvitamin D [25(OH)D] concentrations and regional body fat deposition in 2011-2018 National Health and Nutrition Examination Survey participants aged 18 to 59 years. We hypothesized that serum 25(OH)D concentrations were negatively associated with total, appendicular, and truncal fat deposition. Serum 25(OH)D concentration was categorized into sufficient (≥75.0 nM), insufficient (50.0-74.9 nM), and deficient (<50.0 nM) groups. Fat mass (FM) was measured by dual-energy X-ray absorptiometry, and FM index (FMI) was calculated by dividing FM (kg) with height2 (m2). Multivariant linear regression and Granger causal analysis were performed to assess the causal relationship between vitamin D status and regional FMIs. Overall serum 25(OH)D concentrations were negatively associated with total (β = -0.029, standard error [SE] = 0.002), trunk (β = -0.015, SE = 0.001), arms (β = -0.004, SE = 3.09 × 10-4), and legs (β = -0.010, SE = 0.001) FMIs in all participants (P < .001, respectively); however, after stratified by vitamin D status and BMI, the negative associations were only observed in individuals with vitamin D deficiency and obesity. The causal analysis indicated that serum 25(OH)D concentrations may causally reduce the arms (F = 4.917, probability [P] = 0.007), legs (F = 5.783, P = 0.003), and total (F = 3.202, P = 0.041) FMIs except for trunk FMI but not vice versa. In conclusion, poor vitamin D status was associated with increased total and appendicular body fat deposition in US adults, particularly in participants with obesity.

Association between serum Klotho concentration and hypertension in postmenopausal women, a cross-sectional study from NHANES 2013-2016

BACKGROUND

The objective of this study was to examine the correlation between serum Klotho protein concentration and postmenopausal hypertension.

METHODS

A cross-sectional study design was used, in which 1713 postmenopausal women who participated in the National Health and Nutrition Examination Survey (NHANES) 2013-2016 were included. Multivariate logistic regression models were applied to assess the association between serum Klotho concentration and postmenopausal hypertension.

RESULTS

A weighted analysis was executed, revealing a noteworthy hypertension prevalence rate of 53.44% among the study participants. Participants with lower quartile of serum Klotho concentration had a higher prevalence of hypertension than those in higher quartiles (Q1:62.29% vs. Q2: 48.52% vs. Q3: 47.33% vs. Q4: 55.02%, p < 0.001). Furthermore, a multivariate logistic regression analysis confirmed that participants with higher quartiles of serum Klotho concentration had a significantly reduced risk of postmenopausal hypertension compared to those in the lowest quartile. Subgroup analysis displayed consistent findings in those following subgroups: aged ≥ 65 years, obesity, nonsmokers, individuals without diabetes and coronary heart disease, and those with higher levels of estradiol and estimated glomerular filtration rate. Based on the results, we concluded that there is a significant association between serum Klotho concentration and postmenopausal hypertension.

CONCLUSION

The findings of this study revealed a significant inverse association between serum Klotho concentration and hypertension among postmenopausal women. Serum Klotho concentration may serve as a valuable biomarker for risk stratification in postmenopausal women who are at risk of developing hypertension.

EMAS position statement: Vitamin D and menopausal health

INTRODUCTION

There is increasing evidence that vitamin D has widespread tissue effects. In addition to osteoporosis, vitamin D deficiency has been associated with cardiovascular disease, diabetes, cancer, infections and neurodegenerative disease. However, the effect of vitamin D supplementation on non-skeletal outcomes requires clarification, especially in postmenopausal women.

AIM

This position statement provides an evidence-based overview of the role of vitamin D in the health of postmenopausal women based on observational and interventional studies.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSIONS

Vitamin D status is determined by measuring serum 25-hydroxyvitamin D levels. Concentrations <20 ng/ml (<50 nmol/l) and <10 ng/ml (<25 nmol/l) are considered to constitute vitamin D deficiency and severe deficiency, respectively. Observational data suggest an association between vitamin D deficiency and adverse health outcomes in postmenopausal women, although they cannot establish causality. The evidence from randomized controlled trials concerning vitamin D supplementation is not robust, since many studies did not consider whether people were deficient at baseline. Moreover, high heterogeneity exists in terms of the population studied, vitamin D dosage, calcium co-administration and duration of intervention. Concerning skeletal health, vitamin D deficiency is associated with low bone mass and an increased risk of fractures. Vitamin D supplementation at maintenance doses of 800-2000 IU/day (20-50 μg/day), after repletion of vitamin D status with higher weekly or daily doses, may be of benefit only when co-administered with calcium (1000-1200 mg/day), especially in the elderly populations and those with severe vitamin D deficiency. Concerning cardiovascular disease, vitamin D deficiency is associated with an increased prevalence of cardiovascular risk factors, mainly metabolic syndrome, type 2 diabetes mellitus and dyslipidemia. Vitamin D deficiency, especially its severe form, is associated with an increased risk of cardiovascular events (coronary heart disease, stroke, mortality), independently of traditional risk factors. Vitamin D supplementation may have a modestly beneficial effect on lipid profile and glucose homeostasis, especially in obese individuals or those ≥60 years old and at doses of ≥2000 IU/day (≥50 μg/day). However, it has no effect on the incidence of cardiovascular events. Concerning cancer, vitamin D deficiency is associated with increased incidence of and mortality from several types of cancer, such as colorectal, lung and breast cancer. However, the data on other types of gynecological cancer are inconsistent. Vitamin D supplementation has no effect on cancer incidence, although a modest reduction in cancer-related mortality has been observed. Concerning infections, vitamin D deficiency has been associated with acute respiratory tract infections, including coronavirus disease 2019 (COVID-19). Vitamin D supplementation may decrease the risk of acute respiratory tract infections and the severity of COVID-19 (not the risk of infection). Concerning menopausal symptomatology, vitamin D deficiency may have a negative impact on some aspects, such as sleep disturbances, depression, sexual function and joint pains. However, vitamin D supplementation has no effect on these, except for vulvovaginal atrophy, at relatively high doses, i.e., 40,000-60,000 IU/week (1000-1500 IU/week) orally or 1000 IU/day (25 μg/day) as a vaginal suppository.

L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality of individuals with rheumatoid arthritis

OBJECTIVE

We aimed to examine the relationship between serum 25-hydroxyvitamin D and all-cause, cause-specific mortality of patients with RA.

METHODS

This cohort study included 1466 patients with RA from The National Health and Nutrition Examination Survey (NHANES) 2001-14. Mortality status was obtained according to death certificate records from the National Death Index. Cox proportional risk models were used to estimate hazard ratios (HR) and 95% CI for mortality. A generalized additive model, smooth curve fitting and 2-piecewise Cox proportional hazards models were established to address the nonlinearity between serum 25-hydroxyvitamin D and mortality.

RESULTS

A total of 1466 patients [mean (s.d.) 59.89 (14.14) years old; 58.94% female] were enrolled. The weighted mean level of 25-hydroxyvitamin D was 59.26 (24.99) nmol/l and 38.95% were found with deficient (or severe deficient) vitamin D (<50.00 nmol/l). During 10453 person-years of follow-up, 268 patients were documented for all-cause death, including 52 cardiovascular disease （CVD）deaths and 48 cancer deaths. Compared with patients with serum 25-hydroxyvitamin D <25.00 nmol/l, patients with higher serum 25-hydroxyvitamin D were more likely to have lower rate of all-cause mortality. Nonlinear and L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality was found, and decreased serum 25-hydroxyvitamin D was significantly associated with increased risk of all-cause mortality in patients with serum 25-hydroxyvitamin D <37.30 nmol/l [HR 0.95 (0.92, 0.98); P < 0.01].

CONCLUSION

An L-shaped association between serum 25-hydroxyvitamin D and all-cause mortality was found among patients with RA, indicating that serum 25-hydroxyvitamin D should be improved to a certain level for the prevention of premature death.

Vitamin D, Menopausal Health and COVID-19: Critical Appraisal of Current Data

Inconsistency exists across studies conducted in postmenopausal women regarding the effect of vitamin D deficiency (VDD) and supplementation on several aspects of menopausal health, such as fractures, vasomotor symptomatology, cardiovascular disease (CVD), cancer and infections, including coronavirus disease 2019 (COVID-19). The aim of this review is to critically summarize the evidence provided by observational studies and randomized controlled trials (RCTs) of vitamin D supplementation in postmenopausal women with VDD. Observational studies have found that VDD is associated with an increased risk of falls and fractures after the menopause. VDD also has a negative effect on menopausal symptomatology. VDD, especially its severe form, is associated with an increased risk of CVD risk factors and CVD events. VDD is associated with increased risk and mortality from several cancer types and risk of infections. The evidence from RCTs regarding the effect of vitamin D supplementation on falls, fractures, menopausal symptoms, cardiovascular disease, cancer and infections is not robust. Thus, skeletal health may benefit only when vitamin D is co-administered with calcium, especially in those ≥70 years old and with severe VDD. There is no evidence of a favorable effect on menopausal symptoms or risk of CVD or cancer, except for a modest reduction in cancer-related mortality. Inconsistency still exists regarding its effect on infection risk, disease severity and mortality due to COVID-19.

Serum Vitamin D Levels in Relation to Hypertension and Pre-hypertension in Adults: A Systematic Review and Dose–Response Meta-Analysis of Epidemiologic Studies

Background

Findings of observational studies that evaluated the association of serum vitamin D status and high blood pressure were contradictory. This meta-analysis of epidemiologic studies assessed the relation of serum vitamin D levels to hypertension (HTN) and pre-hypertension in adults.

Methods

We conducted a systematic search of all published articles up to March 2021, in four electronic databases (MEDLINE (PubMed), Web of Science (ISI), Embase and Scopus), and Google scholar. Seventy epidemiologic studies (10 prospective cohort, one nested case–control, and 59 cross-sectional investigations) that reported relative risks (RRs), odds ratios (ORs), hazard ratios, or prevalence ratios with 95% CIs for HTN or pre-hypertension in relation to serum vitamin D concentrations in adults were included in the analysis.

Results

In prospective studies, a 16% decrease in risk of hypertension was observed in participants with high levels of serum vitamin D compared to low levels (RR: 0.84; 95%CI: 0.73, 0.96; 12 effect sizes). Dose–response analysis in prospective studies revealed that each 25 nmol/L increase in serum vitamin D concentrations resulted in 5% reduced risk of HTN (RR: 0.95; 95% CI: 0.90, 1.00). Also, a significant nonlinear relationship between serum vitamin D levels and HTN was found (P_nonlinearity < 0.001). In cross-sectional investigations, highest vs. lowest level of serum vitamin D was related to reduced odds of HTN (OR: 0.84; 95%CI: 0.79, 0.90; 66 effect sizes) and pre-hypertension (OR: 0.75; 0.95%CI: 0.68, 0.83; 9 effect sizes). Dose–response analysis in these studies showed that each 25 nmol/L increase in serum vitamin D levels was related to a significant 6% reduction in odds of hypertension in all populations (RR: 0.94; 95%CI: 0.90, 0.99) and 3% in studies with representative populations (RR: 0.97; 95%CI: 0.95, 0.99).

Conclusion

This meta-analysis of epidemiologic studies disclosed that serum vitamin D concentrations were inversely related to the risk of HTN in adults, in a dose–response manner in both prospective cohort and cross-sectional studies.

Systematic Review Registration:http://www.crd.york.ac.uk/Prospero, identifier: CRD42021251513.

Joint effect of 25-hydroxyvitamin D and secondhand smoke exposure on hypertension in non-smoking women of childbearing age: NHANES 2007-2014

BACKGROUND

Vitamin D deficiency (VDD) may increase the risk of hypertension in women of childbearing age, who may be exposed to secondhand smoke (SHS) simultaneously. Till now, few studies have investigated the joint effects of VDD and SHS on hypertension in this population. We evaluated whether exposure to SHS modified the association between VDD and hypertension.

METHODS

Data from National Health and Nutrition Examination Surveys (NHANES) 2007-2014 were analyzed. Our research subjects were 2826 nonsmoking and nonpregnant women of childbearing age (20-44 years old). Hypertension was defined based either on systolic blood pressure (SBP) ≥ 130 mmHg and/or diastolic blood pressure (DBP) ≥ 80 mmHg or on now taking prescribed medicine for hypertension. The directed acyclic graphs (DAG) and the back-door criterion were used to select a minimal sufficient adjustment set of variables (MSAs) that would identify the unconfounded effect of 25(OH)D and hypertension. The interactive effect of VDD and SHS on hypertension was evaluated by using logistic regression models, followed by strata-specific analyses.

RESULTS

The prevalence of VDD in the hypertension group was significantly higher than that in the non-hypertension group (48.2% vs 41.0%, P = 0.008), as well as the exposure rate of SHS (39.1% vs 33.8%, P = 0.017). VDD was independently associated with nearly 50% increased risk of hypertension [adjusted odds ratio (aOR) = 1.43, 95% confidence interval (CI): 1.01, 2.04], while no significant association was observed between SHS and hypertension. However, SHS showed a significant synergistic effect on VDD with a higher aOR of 1.79 (95% CI: 1.14, 2.80) (P_interaction = 0.011). This synergistic effect was more obvious when stratified by BMI (in overweight women, aOR, 95% CI =4.74, 1.65-13.60 for interaction vs 2.33, 1.01-5.38 for VDD only) and race (in Non-Hispanic Black women, aOR, 95% CI =5.11, 1.58-16.54 for interaction vs 2.69, 1.10-6.62 for VDD only).

CONCLUSION

There exist synergistic effects of SHS and VDD on the prevalence of hypertension in American women of childbearing age, with more significant effects in women who were overweight or Non-Hispanic Black. Further studies are warranted to verify this finding in other populations, and the molecular mechanisms underlying the joint effect of SHS and VDD need to be elucidated.