The effects of acupuncture vs. metformin on lipid metabolism in PMOS patients with insulin resistance: a secondary analysis of a randomized controlled trial

It has been suggested that abnormal lipid metabolism among women with polyendocrine metabolic ovarian syndrome (PMOS) and insulin resistance (IR), including elevated visceral adiposity index (VAI) and disrupted free fatty acid (FFA) metabolism, contributes to long-term cardiometabolic risk. The trial enrolled 342 women aged 18–40 years with PMOS (based on the revised 2004 Rotterdam criteria) and IR, which was defined as homeostatic model assessment of insulin resistance (HOMA-IR) > 2.14 at three hospitals in China. Participants were randomly assigned to the acupuncture, metformin, or sham acupuncture group ( n = 114 per group) for 4 months of treatment followed by 3 months of follow-up. This secondary analysis of a three-arm randomized trial evaluated changes in VAI, FFA, adipose tissue insulin resistance index (Adipose-IR), and insulin sensitivity index for FFAs (ISI-FFA) from baseline to 4 months and 7 months. Between-group and within-group comparisons used two-sample t-tests for normally distributed data and Mann–Whitney U-tests otherwise. Exploratory analyses were stratified by body mass index (BMI) and androgen status. In this exploratory secondary analysis, true acupuncture resulted in a greater VAI reduction compared with sham acupuncture at 4 months (between-group difference: − 0.26; P = 0.023) and a greater FFA reduction at 7 months (between-group difference: − 0.15; P = 0.031). Metformin resulted in a greater improvement in Adipose-IR (between-group difference: − 16.77; P = 0.016) and ISI-FFA (between-group difference: 0.06; P = 0.015) compared with sham acupuncture at 4 months. Direct comparisons between true acupuncture and metformin did not show statistically significant differences for these outcomes. Clinically, these findings suggest that metabolic management of women with PMOS and IR may benefit from monitoring lipid- and adipose-related metabolic markers in addition to conventional measures of IR. The outcome-specific patterns observed with acupuncture and metformin may provide complementary information for metabolic monitoring, although they do not establish treatment selection for individual phenotypes. Because this was an exploratory, unadjusted secondary analysis, the findings remain hypothesis-generating, and they require prospective confirmation with pre-specified metabolic outcomes. This trial was registered in ClinicalTrials.gov (Identification number: NCT02491333) on July 8, 2015.