RESUMEN
BACKGROUND: This systematic review and meta-analysis aimed to investigate the effect of cinnamon on body weight, body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and body fat mass including the maximum number of studies. METHODS: Medline, ISI Web of Science, Scopus, Google Scholar, and Cochrane library were searched with no limitation from inception up to August 2019 for relevant randomized controlled clinical trials (RCTs). The RCTs' risk of bias was assessed using the Cochrane collaboration's tool. Random-effects model was used for meta-analysis. RESULTS: Twenty-one RCTs with 1,480 participants were included. The meta-analysis showed that cinnamon supplementation significantly reduces BMI [weighted mean difference (WMD) = -0.40 kg/m2 , 95% confidence interval (CI): -0.57, -0.22 kg/m2 , p < .001, I2 = 78.9%], body weight (WMD = -0.92 kg; 95% CI: -1.51, -0.33 kg; p = .002; I2 = 84.2%), and WHR (WMD = -0.02, 95% CI: -0.038, -0.018; p < 0.001; I2 = 0%). Cinnamon supplementation did not significantly affect the WC (WMD = -1.76 cm, 95% CI: -3.57, -0.045 cm; p = .056; I2 = 90.8%) and body fat mass (WMD = -0.87%, 95% CI: -1.87, 0.025%; p = .057; I2 = 78.6%). CONCLUSION: Cinnamon supplementation significantly reduces body weight, BMI, and WHR. Future high-quality long-term RCTs are recommended to confirm these results.
Asunto(s)
Cinnamomum zeylanicum , Suplementos Dietéticos/análisis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Peso Corporal/efectos de los fármacos , Ensayos Clínicos como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Circunferencia de la Cintura/efectos de los fármacos , Adulto JovenRESUMEN
It is suggested that vitamin D status is associated with androgenic profile in women with polycystic ovarian syndrome (PCOS). Although several clinical trials are known in this regard, the results were inconsistent. Therefore, this study was aimed to conduct a systematic review and meta-analysis of published clinical trials to elucidate the possible effect of vitamin D supplementation on the androgen levels in adult females with PCOS. PubMed, SCOPUS, and Google Scholar were searched to identify related articles published up to January 2017. Mean ± standard deviation (SD) of changes in serum total testosterone, sex hormone binding globulin (SHBG), and free testosterone were extracted to calculate Hedges' g to be used as effect size for meta-analysis. DerSimonian and Liard random effects model was incorporated to summarize the effects. Six clinical trials with 183 participants aged 18-41 years with follow-up period between 3-24 weeks were included. Our analysis revealed that vitamin D supplementation significantly reduces total testosterone (Hedges' g=-0.32, 95% CI: -0.55 to -0.10; p=0.005); this effect remained significant in single group trials after subgroup analysis. Vitamin D supplementation did not affect serum free testosterone (Hedges' g=-0.21, 95% CI: -0.44 to 0.079; p=0.08) or SHBG levels (Hedges' g=0, 95% CI, 0.22-0.22; p=0.98). The present systematic review and meta-analysis revealed that vitamin D supplementation might significantly affect serum total testosterone while it is not effective in improving other markers of androgenic profile. Future double-blind, placebo-controlled clinical trials are highly recommended.