Alpha lipoic acid reduces markers of inflammation in people with metabolic syndrome, meta-analysis shows
Highlights
- Meta-analysis of 18 randomized, controlled trials with patients with metabolic syndrome and related disorders
- ALA supplementation ranges from 300 to 600 mg/day
- Study duration ranges from 2 weeks to 12 months
- Treatment significantly decreases inflammatory markers CRP, IL-6 and TNF-alpha
Summary
This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to determine the effect of alpha-lipoic acid (ALA) supplementation on inflammatory markers in patients with metabolic syndrome and related disorders. Increased chronic inflammation is associated with an increased risk of type 2 diabetes, arteriosclerosis and other metabolic disorders.
The literature search included RCTs indexed in MEDLINE, EMBASE, Web of Science and Cochrane Library databases up to November 2017. Inclusion criteria included randomized, placebo-controlled trials (either parallel or cross-over designs) involving adults diagnosed with metabolic diseases and reporting mean changes between pre- and post-intervention for the inflammatory markers C-reactive protein (CRP), interleukin 6 (IL-6) and/or tumor necrosis factor alpha (TNF-alpha) following ALA supplementation for the intervention and placebos groups.
Study quality was assessed using the Cochrane risk of bias tool. Data were pooled by using the random-effect model, and the standardized mean difference (SMD) was considered as the summary effect size. Statistical heterogeneity was assessed using Cochran’s Q and I-square (I2) tests. Publication bias and subgroup analyses were also performed.
A total of 18 studies published between 2005 and 2017 met the inclusion criteria and were included in the meta-analysis. The duration of study interventions varied from 2 weeks to 12 months, and ALA dosages ranged from 300 to 600 mg/day.
Results indicate that ALA supplementation significantly decreased CRP (SMD: -1.52; 95% CI, -2.25, -0.80; P<.001), IL-6 (SMD: -1.96; 95% CI, -2.60, -1.32; P<.001), and TNF-alpha (SMD: -2.62; 95% CI, -3.70, -1.55; P<.001) in this patient population.
These findings indicate that ALA supplementation (300 to 600 mg/day) may offer clinical value to reduce inflammatory markers such as CRP, IL-6 and TNF-alpha in patients with metabolic syndrome and related disorders.
