Metabolically healthy and unhealthy obesity and risk of vasomotor symptoms in premenopausal women: cross-sectional and cohort studies

Objective: To examine the relationship between metabolically healthy and unhealthy obesity phenotypes and risk of vasomotor symptoms (VMS) in premenopausal women. Design: Prospective cohort study. Setting: Middle-aged women in a cohort based on regular health screening examinations. Population: Premenopausal Korean women aged 42–52 years were recruited and were followed up for a median of 4.2 years. The cross-sectional and cohort studies comprised 4672 women and 2590 women without VMS at baseline, respectively. Methods: Adiposity measures included body mass index (BMI), waist circumference and percentage body fat. Being metabolically healthy was defined as not having any metabolic syndrome components or a homeostasis model assessment of insulin resistance of 2.5 or more. Main outcomes measures: VMS (hot flushes and night sweats) assessed using the questionnaire. Results: All adiposity measures were positively associated with an increased risk of VMS in both cross-sectional and longitudinal studies. The multivariable-adjusted prevalence ratio (95% confidence interval [CI]) for VMS comparing percentage body fat of 35% or more with the reference was 1.47 (95% CI 1.14–1.90) in metabolically healthy women, and the corresponding prevalence ratio was 2.32 (95% CI 1.42–3.78) in metabolically unhealthy women (P_interaction = 0.334). The multivariable-adjusted hazard ratio for incident VMS comparing percentage body fat of 35% or more with the reference was 1.34 (95% CI 1.00–1.79) in metabolically healthy women, whereas the corresponding hazard ratio was 3.61 (95% CI 1.81–7.20) in metabolically unhealthy women (P_interaction = 0.036). The association between BMI, waist circumference and VMS did not significantly differ by metabolic health status. Conclusions: Maintaining normal weight and being metabolically healthy may help to prevent VMS in premenopausal women. Tweetable abstract: Avoiding obesity and a metabolically unhealthy status may help reduce vasomotor symptoms in premenopausal women.