Effects of Alpha-lipoic Acid Supplementation on Human Diabetic Nephropathy: A Systematic Review and Meta-analysis.

BACKGROUND: Diabetic nephropathy (DN) is kidney dysfunction, which occurs due to elevated urine albumin excretion rate and reduced glomerular filtration rate. Studies on animals have shown that alpha-lipoic acid (ALA) supplementation can reduce the development of DN. OBJECTIVES: We performed a systematic review and meta-analysis to examine the effects of ALA supplementation on biological indices (albumin, creatinine, etc.) indicative of human DN. METHODS: The search procedure included PubMed Central, Embase, Cochrane Library (trials), and Web of Science (protocol registration: INPLASY202060095). RESULTS: We found that ALA supplementation decreased 24h urine albumin excretion rate in patients with diabetes (standardized mean difference=-2.27; confidence interval (CI)=(-4.09)-(-0.45); I2=98%; Z=2.44; p=0.01). A subgroup analysis revealed that the results of studies examining only ALA did not differ from those examined ALA in combination with additional medicines (Chisquared= 0.19; p=0.66; I2=0%), while neither ALA nor ALA plus medication had an effect on 24h urine albumin excretion rate (p>0.05). Also, ALA supplementation decreased urine albumin mg/l (mean difference (MD)=-12.95; CI=(-23.88)-(-2.02); I2=44%; Z=2.32; p=0.02) and urine albumin to creatinine ratio (MD=-26.96; CI=(-35.25)-(-18.67); I2=0%; Z=6.37; p<0.01) in patients with diabetes. When the studies examining ALA plus medication were excluded, it was found that ALA supplementation had no effect on urine albumin mg/l (p>0.05) but did significantly decrease urine albumin to creatinine ratio (MD=-25.88, CI=(34.40-(-17.36), I2=0%, Z=5.95, p<0.00001). CONCLUSION: The available evidence suggests that ALA supplementation does not improve biological indices that reflect DN in humans. Overall, we identified limited evidence, and therefore, the outcomes should be considered with caution.

Effects of Nutrition/Diet on Brown Adipose Tissue in Humans: A Systematic Review and Meta-Analysis.

BACKGROUND: Brown adipose tissue (BAT) provides a minor contribution to diet-induced thermogenesis (DIT)-the metabolic response to food consumption. Increased BAT activity is generally considered beneficial for mammalian metabolism and has been associated with favorable health outcomes. The aim of the current systematic review was to explore whether nutritional factors and/or diet affect human BAT activity. METHODS: We searched PubMed Central, Embase and Cochrane Library (trials) to conduct this systematic review (PROSPERO protocol: CRD42018082323). RESULTS: We included 24 eligible papers that studied a total of 2785 participants. We found no mean differences in standardized uptake value of BAT following a single meal or after 6 weeks of L-Arginine supplementation. Resting energy expenditure (REE), however, was increased following a single meal and after supplementation of capsinoid and catechin when compared to a control condition (Z = 2.41, p = 0.02; mean difference = 102.47 (95% CI = 19.28-185.67)). CONCLUSIONS: Human BAT activity was not significantly affected by nutrition/diet. Moreover, REE was only increased in response to a single meal, but it is unlikely that this was due to increased BAT activity. BAT activity assessments in response to the chronic effect of food should be considered along with other factors such as body composition and/or environmental temperature.

Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia.

We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2 °C) following exertional hyperthermia (rectal temperature ≥39.5 °C) in a physically heterogeneous group of men and women (n = 62). Lean body mass was the only significant predictor of cooling time following CWI (R2 = 0.137; P < 0.001); however, that prediction did not provide the precision (mean residual square error: 3.18 ± 2.28 min) required to act as a safe alternative to rectal temperature measurements.

Developing and testing an instrument to assess aquaticity in humans.

We developed and validated an aquaticity assessment test (AAT) for the evaluation of human physical adequacy in the water. Forty-six volunteers (25M/21F; 20 ± 8 years) participated and performed 10 easy-to-administer and practical aquatic tasks. Group A was formed by 36 elite athletes (M/F 20/16, 24.7 ± 10yrs) from two sports categories depending on their affinity to the water environment: terrestrial (wrestling, cycling, dancing) and aquatic (swimming, synchronized swimming, free diving) sports. Group B was formed by 10 non-athlete participants (5M/5F, 14.4 ± 1.4yrs) and was assessed by two independent evaluators. Participants in Group A performed the aquatic tasks once to develop the final AAT items and cutoffs. Participants in Group B performed the aquatic tasks twice on different days to assess repeatability. Factor analysis recommended all 10 aquatic tasks to be included in the final AAT, resulting in scores ranging from 9.5 to 49.5. The AAT scores were statistically different between the terrestrial and the aquatic sports' participants (p < 0.001). The duration of the test was 25 min from the time of water entry. Receiver operating characteristics curve analyses demonstrated that the cutoffs for low and high aquaticity levels in this sample were ≤23.7 and ≥43.3, respectively. Reliability analyses demonstrated that the aquaticity scores obtained on different days and by different examiners highly correlated (p < 0.001) and were not significantly different (p > 0.05). The AAT appears to be a valid and reliable tool for the evaluation of human physical adequacy in the water. It is an easy and user-friendly test which can be performed in any swimming pool without a need for highly trained staff and specialized equipment, however more research needs to be done in order to be applied in other population group.