Sex and obesity status modify the association between vitamin D and eczema among adolescents.

BACKGROUND: Epidemiologic studies have reported inconsistent associations between vitamin D and eczema. This study sought to assess whether sex and obesity status could modify the association between vitamin D and eczema. METHODS: A cross-sectional study enrolled 763 adolescents in Kuwait. 25-hydroxyvitamin D (25(OH)D) was measured in venous blood. Current eczema was defined according to clinical history and characteristic morphology and distribution. RESULTS: In sex-stratified analysis, decreased 25(OH)D levels were associated with increased current eczema prevalence among males (adjusted odds ratio (aOR)tertile 1 vs. tertile 3: 2.14, 95% confidence intervals (CI): 1.07-4.56), but not among females (aORtertile 1 vs. tertile 3: 1.08, 95% CI: 0.71-1.66). Further stratification by obesity status showed that lower 25(OH)D levels were associated with increased current eczema prevalence among overweight/obese males (per 10-unit decrease in 25(OH)D levels: aOR: 1.70, 95% CI: 1.17-2.46). Such an association was weaker and statistically non-significant among overweight/obese females (per 10-unit decrease in 25(OH)D levels: aOR: 1.26, 95% CI: 0.93-1.70). CONCLUSIONS: Sex and obesity status modified the association between vitamin D levels and eczema, with an inverse association observed among overweight/obese males, but not among overweight/obese females. These results suggest that preventive and clinical management strategies could vary by sex and obesity status. IMPACT: The current study showed that sex and obesity modify the association between vitamin D and eczema among adolescents. An inverse association between vitamin D and eczema was observed among overweight/obese males, but this association was not as pronounced among overweight/obese females. Vitamin D was not associated with eczema among underweight/normal weight males and females. The identification of effect modification by sex and obesity status add to the current scientific knowledge and further highlight the complexity of the association between vitamin D and eczema. These results may promote a more individualized approach to the future prevention and clinical management of eczema.

Sex differences in the association between vitamin D and prediabetes in adults: A cross-sectional study.

BACKGROUND/OBJECTIVES: Vitamin D status has been shown to be associated with prediabetes risk. However, epidemiologic evidence on whether sex modulates the association between vitamin D and prediabetes is limited. The present study investigated sex-specific associations between vitamin D and prediabetes. SUBJECTS/METHODS: The Kuwait Wellbeing Study, a population-based cross-sectional study, enrolled nondiabetic adults. Prediabetes was defined as 5.7 ≤ HbA1c% ≤6.4; 25-hydroxyvitamin D (25(OH)D) was measured in venous blood and analyzed as a continuous, dichotomous (deficiency: <50 nmol/L vs. insufficiency/sufficiency ≥50 nmol/L), and categorical (tertiles) variable. Associations were evaluated by estimating adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs), while stratifying by sex. RESULTS: A total of 384 participants (214 males and 170 females) were included in the current analysis, with a median age of 40.5 (interquartile range: 33.0-48.0) years. The prevalence of prediabetes was 35.2%, and 63.0% of participants had vitamin D deficiency. Assessments of statistical interaction between sex and 25(OH)D status were statistically significant (PSex × 25(OH)D Interaction < 0.05). In the sex-stratified analysis, after adjustment for confounding factors, decreased 25(OH)D levels were associated with increased prevalence of prediabetes in males (aPRDeficiency vs. In-/Sufficiency: 2.35, 95% CI: 1.36-4.07), but not in females (aPRDeficiency vs. In-/Sufficiency: 1.03, 95% CI: 0.60-1.77). Moreover, the prevalence of prediabetes differed between males and females at 25(OH)D levels of ≤35 nmol/L, with a higher prevalence of prediabetes in males compared to females. Such a sex-specific difference was not observed at 25(OH)D levels of >35 nmol/L. CONCLUSIONS: Sex modified the association between vitamin D levels and prediabetes, with an inverse association observed among males, but not among females. Moreover, the observed sex-disparity in the prevalence of prediabetes was only pronounced at 25(OH)D levels of ≤35 nmol/L.

Pilot Study of the Feasibility of a Worksite Plant-Based Diabetes Prevention Program.

Introduction: This study aimed to explore the feasibility and acceptability of implementing a worksite diabetes prevention program-Beat Diabetes-on the basis of a plant-based diet and encouragement of physical activity. Methods: This was a mixed-methods pilot study using a 1-group pretest‒post-test design. The participants were university employees. A 13-week group-based intervention adapted from the Diabetes Prevention Program to emphasize a plant-based diet and on the basis of the Health Action Process Approach. Program implementation and participant acceptability were assessed through surveys, weekly documentation of the process, and individual interviews. Consumption of healthy and less healthy plant-based foods and animal-based foods, physical activity, and Health Action Process Approach‒based psychosocial determinants were measured through questionnaires before and after the program, as was blood glucose. Weights were measured weekly. Results: A total of 14 participants were enrolled, with 93% retention. Program implementation was feasible and highly acceptable to participants and also resulted in significant improvements in weight, healthy relative to less healthy plant-based and animal-based foods, vigorous physical activity, blood glucose, and psychosocial determinants of behavior change. Conclusions: On the basis of our pilot study, conducting a worksite plant-based diabetes prevention program was feasible and acceptable and elicited positive changes in physiologic, behavioral, and psychosocial variables related to the risk of diabetes.