All-cause mortality risk of metabolically healthy abdominal obese individuals: the EPIC-MORGEN study

Abstract

Objective: It appears that a certain proportion of obese individuals have a normal metabolic profile despite having excess weight. Whether these so-called "metabolically healthy" obese express lower disease and mortality risks than "metabolically unhealthy" obese is still unclear. The mortality risk of "metabolically healthy" abdominal obese (MHAO) individuals was investigated.

Design and methods: Prospective cohort study (EPIC-MORGEN) among 22,654 individuals aged 20-59 years followed for an average of 13.4 years (SD 2.3). MHAO was assessed at baseline (1993-1997) and defined as abdominal obesity (waist circumference ≥102 cm/≥88 cm (men/women)) with normal glucose, blood pressure, and plasma lipids. All-cause mortality risks adjusted for age and sex were estimated using Cox proportional hazards models.

Results: Individuals who were "metabolically healthy" nonabdominal obese (MHNAO) comprised the reference group. As compared to MHNAO, mortality risk for MHAO was around 40% higher (Hazard ratio (HR) 1.43; 95% confidence interval (CI): 1.00-2.04) and of the same magnitude as that for "metabolically unhealthy" nonabdominal obese (MUNAO) (HR 1.31; 95% CI: 1.08-1.59). The HR for MUAO was 1.99 (95% CI: 1.62-2.43).

Conclusions: Mortality risk of MHAO individuals was significantly higher than that of MHNAO individuals and lower than, but not statistically significantly different from, that of MUAO individuals.