PURPOSE OF REVIEW:Low vitamin D levels have been extensively reported in obesity. Thus, the pandemic of obesity has been paralleled by a high prevalence of low vitamin D status. Given the well documented associations linking poor vitamin D status to adverse health outcomes (diabetes, cardiovascular disease, cancers, all-cause mortality), a proper understanding of the mechanisms linking excess adiposity to low vitamin D status is key to identify and implement effective interventions to replenish vitamin D levels in obese individuals. In this review, we will discuss recent literature investigating the effects of adipose tissue volume loss through energy restriction and/or physical activity on circulating 25-hydroxyvitamin D [25(OH)D] levels.

RECENT FINDINGS:Improvements of circulating 25(OH)D levels with adiposity loss through lifestyle interventions without supplementation is being reported by a growing number of studies, including recent randomized controlled trials.

SUMMARY:Low 25(OH)D is one of the metabolic disturbances associated with excess adiposity, particularly visceral adiposity. Recommendations for the treatment of obesity-related vitamin D deficiency should emphasize the role of visceral adiposity loss through healthy lifestyle habits, in conjunction with weight-adjusted vitamin D supplementation, not only to replenish 25(OH)D levels but also to address other visceral adiposity-related disturbances, such as insulin resistance, inflammation, hypertension, and dyslipidemia.

BACKGROUND: It is currently unknown whether dietary weight loss interventions can induce regression of carotid atherosclerosis. METHODS AND RESULTS: In a 2-year Dietary Intervention Randomized Controlled Trial-Carotid (DIRECT-Carotid) study, participants were randomized to low-fat, Mediterranean, or low-carbohydrate diets and were followed for changes in carotid artery intima-media thickness, measured with standard B-mode ultrasound, and carotid vessel wall volume (VWV), measured with carotid 3D ultrasound. Of 140 complete images of participants (aged 51 years; body mass index, 30 kg/m(2); 88% men), higher baseline carotid VWV was associated with increased intima-media thickness, age, male sex, baseline weight, blood pressure, and insulin levels (P<0.05 for all). After 2 years of dietary intervention, we observed a significant 5% regression in mean carotid VWV (-58.1 mm(3;) 95% confidence interval, -81.0 to -35.1 mm(3); P<0.001), with no differences in the low-fat, Mediterranean, or low-carbohydrate groups (-60.69 mm(3), -37.69 mm(3), -84.33 mm(3), respectively; P=0.28). Mean change in intima-media thickness was -1.1% (P=0.18). A reduction in the ratio of apolipoprotein B(100) to apolipoprotein A1 was observed in the low-carbohydrate compared with the low-fat group (P=0.001). Participants who exhibited carotid VWV regression (mean decrease, -128.0 mm(3); 95% confidence interval, -148.1 to -107.9 mm(3)) compared with participants who exhibited progression (mean increase, +89.6 mm(3); 95% confidence interval, +66.6 to +112.6 mm(3)) had achieved greater weight loss (-5.3 versus -3.2 kg; P=0.03), greater decreases in systolic blood pressure (-6.8 versus -1.1 mm Hg; P=0.009) and total homocysteine (-0.06 versus +1.44 mumol/L; P=0.04), and a higher increase of apolipoprotein A1 (+0.05 versus -0.00 g/L; P=0.06). In multivariate regression models, only the decrease in systolic blood pressure remained a significant independent modifiable predictor of subsequent greater regression in both carotid VWV (beta=0.23; P=0.01) and intima-media thickness (beta=0.28; P=0.008) levels. CONCLUSIONS: Two-year weight loss diets can induce a significant regression of measurable carotid VWV. The effect is similar in low-fat, Mediterranean, or low-carbohydrate strategies and appears to be mediated mainly by the weight loss-induced decline in blood pressure. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique Identifier: NCT00160108.

BACKGROUND:The current study was performed to determine the effects of cumin cyminum L. intake on weight loss and metabolic profiles among overweight subjects.

METHODS:This randomized double-blind placebo-controlled clinical trial was conducted among 78 overweight subjects (male, n = 18; female, n = 60) aged 18-60 years old. Participants were randomly assigned into three groups to receive: (1) cumin cyminum L. capsule (n = 26); (2) orlistat120 capsule (n = 26) and (3) placebo (n = 26) three times a day for 8 weeks. Anthropometric measures and fasting blood samples were taken at baseline and after 8 weeks of intervention.

RESULTS:Consumption of the Cuminum cyminum L. and orlistat120 resulted in a similar significant decrease in weight (-1.1± 1.2 and -0.9 ± 1.5 vs. 0.2 ± 1.5 kg, respectively, p = 0.002) and BMI (-0.4 ± 0.5 and -0.4 ± 0.6 vs. 0.1 ± 0.6 kg/m(2), respectively, p = 0.003) compared with placebo. In addition, taking Cuminum cyminum L., compared with orlistat and placebo, led to a significant reduction in serum insulinlevels (-1.4 ± 4.5 vs. 1.3 ± 3.3 and 0.3 ± 2.2 µIU/ml, respectively, p = 0.02), HOMA-B (-5.4 ± 18.9 vs. 5.8 ± 13.3 and 1.0 ± 11.0, respectively, p = 0.02) and a significant rise in QUICKI (0.01 ± 0.01 vs. -0.005 ± 0.01 and -0.004 ± 0.01, respectively, p = 0.02).

CONCLUSION:Taking cumin cyminum L. for eight weeks among overweight subjects had the same effects of orlistat120 on weight and BMI and beneficial effects on insulin metabolism compared with orlistat120 and placebo.© 2015 S. Karger AG, Basel.

Previous investigators have demonstrated in patients with obstructive sleep apnea that weight reduction results in a decrease in apnea severity. Although the mechanism for this decrease is not clear, we hypothesize that decreases in upper airway collapsibility account for decreases in apnea severity with weight loss. To determine whether weight loss causes decreases in collapsibility, we measured the upper airway critical pressure (Pcrit) before and after a 17.4 +/- 3.4% (mean +/- SD) reduction in body mass index in 13 patients with obstructive sleep apnea. Thirteen weight-stable control subjects matched for age, body mass index, gender (all men), and non-REM disordered breathing rate (DBR) also were studied before and after usual care intervention. During non-REM sleep, maximal inspiratory airflow was measured by varying the level of nasal pressure and Pcrit was determined by the level of nasal pressure below which maximal inspiratory airflow ceased. In the weight loss group, a significant decrease in DBR from 83.3 +/- 31.0 to 32.5 +/- 35.9 episodes/h and in Pcrit from 3.1 +/- 4.2 to -2.4 +/- 4.4 cm H2O (p less than 0.00001) was demonstrated. Moreover, decreases in Pcrit were associated with nearly complete elimination of apnea in each patient whose Pcrit fell below -4 cm H2O. In contrast, no significant change in DBR and a minimal reduction in Pcrit from 5.2 +/- 2.3 to 4.2 +/- 1.8 cm H2O (p = 0.031) was observed in the "usual care" group. We conclude that (1) weight loss is associated with decreases in upper airway collapsibility in obstructive sleep apnea, and that (2) the resolution of sleep apnea depends on the absolute level to which Pcrit falls.