Does metabolic health in overweight and obesity persist? – Individual variation and cardiovascular mortality over two decades

Abstract

Objective Overweight and obese individuals may be metabolically healthy, but attention needs to be given to long-term persistence of this trait and any associated variation in cardiovascular risk. Design Cross-sectional and longitudinal variation in metabolic health and associated cardiovascular mortality were analysed in 1099 white European-origin normal-weight and overweight or obese males followed for 20years. Methods Definitions of metabolic health were based on LDL and HDL cholesterol, triglycerides, blood pressure, fasting glucose and cardiovascular risk. Insulin resistance (e.g. HOMA-IR) and sub-clinical inflammation (ESR and white blood cell count) were explored. Cardiovascular mortality risks and persistence of metabolic health status were evaluated. Results There were 87 cardiovascular deaths. Insulin resistance was increased in metabolically healthy overweight or obese participants (median HOMA-IR 2.63, 95% CI: 1.79–3.65, P<0.001) relative to normal-weight participants (median HOMA-IR 1.67, 95% CI: 1.08–2.67, P<0.001) as was sub-clinical inflammation but metabolically healthy overweight or obese individuals were not at increased risk of cardiovascular mortality compared with the metabolically healthy normal-weight individuals (hazard ratio 1.13, 95% CI: 0.34–3.72, P=0.8). The proportions of initially metabolically healthy overweight or obese who remained metabolically healthy for visits 2, 3 and 4 were 54, 48 and 39% respectively, and for initially normal-weight individuals, 68, 51 and 41%. A lower proportion of metabolically healthy overweight or obese individuals remained metabolically healthy at visit 2 compared with normal-weight individuals (P=0.007), but proportions converged thereafter. Conclusions Despite being insulin resistant and having greater sub-clinical inflammation, and despite instability in metabolic health status, metabolically healthy overweight or obese individuals were at no greater risk of cardiovascular mortality than their normal-weight equivalents.