Physicians' Academy for Cardiovascular Education

Individuals with ‘Metabolically healthy obesity’ are actually not healthy

Are people with metabolically healthy obesity really healthy? A prospective cohort study of 381,363 UK Biobank participants

Literature - Zhou Z, Macpherson J, Gray SR et al. - Diabetologia. 2021 Jun 10. doi: 10.1007/s00125-021-05484-6.

Introduction and methods

Obesity is associated with the development of metabolic dysfunctions such as hypertension, dyslipidemia, elevated blood glucose, insulin resistance and systemic inflammation [1]. However, a subset of people with obesity have a normal metabolic profile. These people are sometimes referred to as having ‘metabolically healthy obesity’ [2,3]. Studies have shown mixed result on whether people with metabolically healthy obesity have an increased risk of ASCVD and all-cause mortality [4-6]. This study used data from the UK Biobank to determine the association of metabolically healthy obesity with ASCVD, HF, diabetes, respiratory diseases and all-cause mortality.

The UK biobank is a prospective cohort study which included 502,493 participants from the general population in the UK [7]. A total of 381,363 participants who were not underweight and had complete data on height, weight, BP and blood-based biomarkers were included in the analysis of this study. Metabolic health was defined as a binary condition using BP, CRP, triacylglycerols, LDL-c, HDL-c and HbA1c. Cutt-off values to define metabolically healthy were adapted from another study [8]. Fulfillment of at least 4 out of 6 criteria was considered metabolically healthy and a BMI ≥30 kg/m² was classified as obese. Participants were categorized as having metabolically healthy non-obesity (reference group, n=208 625, 54.7%), metabolically healthy obesity (n=25 103, 9.2%), metabolically unhealthy non-obesity (n=78 259, 20.5%), or metabolically unhealthy obesity (n=59 376, 15.6%). Investigated outcomes were incident diabetes and incident and fatal ASCVD, HF and respiratory diseases. Median follow-up was 11.2 (IQR 10.3-11.9) years.

Main results


People with metabolically healthy obesity had a significantly higher risk of diabetes, ASCVD, HF, respiratory diseases and all-cause mortality, compared with people with metabolically healthy non-obesity. Based on these results, the authors concluded that ‘Using the label ‘metabolically healthy’ to describe this group in clinical medicine is misleading and therefore should be avoided’.


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Find this article online at Diabetologia.

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