Abdominal Obesity and Risk of Hip Fracture: A Systematic Review and Meta-Analysis of Prospective Studies.

Data on the association between general obesity and hip fracture were summarized in a 2013 meta-analysis; however, to our knowledge, no study has examined the association between abdominal obesity and the risk of hip fracture. The present systematic review and meta-analysis of prospective studies was undertaken to summarize the association between abdominal obesity and the risk of hip fracture. We searched online databases for relevant publications up to February 2017, using relevant keywords. In total, 14 studies were included in the systematic review and 9 studies, with a total sample size of 295,674 individuals (129,964 men and 165,703 women), were included in the meta-analysis. Participants were apparently healthy and aged ≥40 y. We found that abdominal obesity (defined by various waist-hip ratios) was positively associated with the risk of hip fracture (combined RR: 1.24, 95% CI: 1.05, 1.46, P = 0.01). Combining 8 effect sizes from 6 studies, we noted a marginally significant positive association between abdominal obesity (defined by various waist circumferences) and the risk of hip fracture (combined RR: 1.36; 95% CI: 0.97, 1.89, P = 0.07). This association became significant in a fixed-effects model (combined effect size: 1.40, 95% CI: 1.25, 1.58, P < 0.001). Based on 5 effect sizes, we found that a 0.1-U increase in the waist-hip ratio was associated with a 16% increase in the risk of hip fracture (combined RR: 1.16, 95% CI: 1.04, 1.29, P = 0.007), whereas a 10-cm increase in waist circumference was not significantly associated with a higher risk of hip fracture (combined RR: 1.13, 95% CI: 0.94, 1.36, P = 0.19). This association became significant, however, when we applied a fixed-effects model (combined effect size: 1.21, 95% CI: 1.15, 1.27, P < 0.001). We found that abdominal obesity was associated with a higher risk of hip fracture in 295,674 individuals. Further studies are needed to test whether there are associations between abdominal obesity and fractures at other bone sites.

Comparative effects of carbohydrate versus fat restriction on serum levels of adipocytokines, markers of inflammation, and endothelial function among women with the metabolic syndrome: a randomized cross-over clinical trial.

BACKGROUND AND AIMS: Despite the efficacy of low-carbohydrate diets in the management of metabolic syndrome (MetS), it remains unknown if these favorable effects are mediated through changes in inflammation and endothelial dysfunction. We aimed to assess the effects of moderate substitution of dietary fats for carbohydrates on serum levels of adipocytokines, inflammatory indices, and biomarkers of endothelial function among women with the MetS. METHODS: In a randomized cross-over clinical trial, 30 overweight or obese (BMI >25) women with the MetS were randomly allocated to follow either a high-carbohydrate (HC) (60-65% carbohydrates, 20-25% fats) diet or a moderately restricted carbohydrate (MRC) (43-47% carbohydrate, 36-40% fats) diet, each for 6 weeks. After a 2-week washout period, individuals were switched to the alternate diet for an additional 6 weeks. In a fasted state, markers of inflammation [high-sensitivity C-reactive protein (hs-CRP), high-sensitivity interleukin-6 (hs-IL-6), high-sensitivity tumor necrosis factor-α (hs-TNF-α), and serum amyloid A (SAA)], endothelial function [E-selectin, serum intercellular adhesion molecule 1 (sICAM-1), and serum vascular cell adhesion molecule 1 (sVCAM-1)], and adipocytokines (leptin and adiponectin) were measured in both study arms at baseline and after 6 weeks. RESULTS: Consumption of an HC diet was associated with increased levels of SAA (3.27 ± 1.22 µg/ml) and decreased levels of adiponectin (-1.68 ± 2.30 ng/ml), while consumption of an MRC diet did not result in such unfavorable effects. Serum concentrations of leptin were reduced by the HC diet (p = 0.02), while they were not affected by the MRC diet. Changes in serum leptin levels were not significant between the two diets (p = 0.09). Serum concentrations of hs-CRP, hs-TNF-α, and IL-6 were not influenced by either diet. No significant differences between the two diets were found in terms of their effect on sICAM-1 and sVCAM-1 concentrations. Adherence to both diets resulted in a 9 ng/ml decrease in serum E-selectin levels (p < 0.05 for both). CONCLUSIONS: Partial replacement of dietary carbohydrates by unsaturated fats prevents the increased levels of markers of systemic inflammation among women with the MetS.