1.
The Effects of Irvingia gabonensis Seed Extract Supplementation on Anthropometric and Cardiovascular Outcomes: A Systematic Review and Meta-Analysis.
Lee, J, Chung, M, Fu, Z, Choi, J, Lee, HJ
Journal of the American College of Nutrition. 2020;(5):388-396
Abstract
Background: It has been hypothesized that Irvingia gabonensis can promote weight loss by increasing fatty acid breakdown and inhibiting fatty acid synthesis.Objective: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of Irvingia gabonensis seed extract supplementation on weight-related health outcomes.Methods: Literature searches were conducted in 4 databases from January 2018 to identify randomized controlled trials (RCTs) investigating the effects of Irvingia gabonensis seed extract supplementation on anthropometric measures and cardiovascular biomarkers. Two investigators independently performed abstract screenings, full-text screenings, data extraction, and risk of bias (ROB) assessments. Random effects meta-analyses were performed when 3 or more RCTs reported the same outcome.Results: Five RCTs met the eligibility criteria for this systematic review. Four of the 5 RCTs were rated as having a high ROB, and only one RCT was rated as having a low ROB. Random-effects meta-analysis of the 5 RCTs showed that a significant decrease in body weight, body fat, and waist circumference was observed in relation to Irvingia gabonensis seed extract supplementation. However, the only one low-ROB trial did not have significantly different outcomes. Meta-analysis also showed beneficial effects of Irvingia gabonensis seed extract supplementation on total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides. Only the low-ROB trial showed a trend of increasing HDL-cholesterol levels (net percent change = 11.61%; 95% confidence interval (CI: -6.12%, 29.34%) and decreasing triglyceride levels (net percent change = -29%; 95% CI: -76%, 19%). The reported adverse events were minor in these 5 RCTs.Conclusions: Overall efficacy of Irvingia gabonensis seed extract supplementation on weight loss seems positive but is limited due to poor methodological quality and the insufficient reporting of the clinical trials. Further high quality RCTs are needed to determine the effectiveness of Irvingia gabonensis seed extract supplement on the weight-related health outcomes.
2.
Effects of weight reduction on serum vaspin concentrations in obese subjects: modification by insulin resistance.
Chang, HM, Lee, HJ, Park, HS, Kang, JH, Kim, KS, Song, YS, Jang, YJ
Obesity (Silver Spring, Md.). 2010;(11):2105-10
Abstract
Visceral adipose tissue-derived serpin (vaspin) has been regarded as a novel adipokine with potential insulin sensitizing properties. We investigated the changes of serum vaspin concentration in response to weight reduction, and the associations between changes in serum vaspin concentrations and changes of anthropometric and metabolic variables in obese subjects after weight reduction. We performed a longitudinal clinical intervention study on 63 obese persons enrolled in a 12-week weight reduction program that included lifestyle modification and adjuvant treatment with the antiobesity agent orlistat. Anthropometric variables, lipid profiles, fasting glucose, fasting insulin, and serum vaspin concentrations were measured. Statistical analyses were performed according to the homeostasis model assessment of insulin resistance (HOMA(IR)). Serum vaspin concentrations decreased significantly in responders (≥2% reduction in baseline weight), but not in nonresponders (<2% reduction in baseline weight). Changes in serum vaspin concentrations were significantly correlated with body weight, BMI, waist circumference, and hip circumference in the higher, but not in the lower, HOMA(IR) group. In multivariate linear regression analysis, change in serum vaspin concentrations in the higher, but not in the lower, HOMA(IR) group was positively correlated with change in BMI and negatively correlated with initial HOMA(IR) level. The associations between changes in serum vaspin concentrations and changes in anthropometric and metabolic parameters differed according to insulin resistance status in obese subjects. These relationships were more prominent in the higher HOMA(IR) group. Insulin resistance may influence the correlations between changes in serum vaspin concentration and related metabolic variables.