Metabolically Healthy Obesity May Increase Risk of Heart Failure, but Not Heart Attack or Stroke

Metabolically healthy obesity (MHO) was associated with a greater risk of developing heart failure (HF) and atrial fibrillation (AF), but not myocardial infarction (MI), stroke, or cardiovascular (CV) death, according to a large nationwide study from France.

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The findings—presented at the 57th European Association for the Study of Diabetes annual meeting, held virtually from September 28 to October 1, 2021—also indicated that persons without obesity can have metabolic abnormalities and be at a high risk for CV events.

“This new and best available evidence tells us that on a population level, the idea that large numbers of people can be obese but metabolically healthy is simply untrue,” said lead author Laurent Fauchier, MD, Centre Hospitalier Universitaire Trousseau, Tours, France, in a press release.

"Encouraging weight loss in people with obesity, regardless of whether or not they are metabolically healthy, will help prevent atrial fibrillation and heart failure. Our findings also highlight the importance of preventing poor metabolic health and suggest that even normal weight individuals may benefit from early behavioural and medical management to improve their diet and increase physical activity in order to guard against stroke,” added Dr Fauchier.

Metabolic abnormalities such as hypertension (HTN), dyslipidemia, and diabetes are commonly associated with obesity, however, some patients with obesity can be free of these metabolic abnormalities.

Research on whether MHO is associated with cardiovascular disease in the absence of metabolic risk factors has yielded conflicting results. To investigate further, Dr Fauchier and colleagues examined medical records of all patients discharged from French hospitals in 2013 with at least 5 years of follow-up.

Approximately 2.9 million individuals, among whom 272 838 (9.5%) had obesity, without a history of major adverse CV events (MACE) and were not underweight at the start of the study were divided into groups by body mass index and 3 metabolic abnormities: diabetes, HTN, and hyperlipidemia. Researchers adjusted for age, sex, and smoking status at baseline.

During 14.1 million person-years of follow-up, researchers identified 510 439 patients with new-onset MACE-HF, which included 77 924 patients with MI, 391 637 patients with HF, 84 042 patients with ischemic stroke, and 100 633 CV deaths. In addition, 257 289 patients developed AF during follow-up, according to the study.

During a mean follow-up of 4.9 years, when researchers pooled men and women, participants with MHO had a higher risk of MACE-HF (multivariate-adjusted hazard ratio [HR]=1.22; 95% CI, 1.19-1.24), new-onset HF (HR=1.34; 95% CI, 1.31-1.37), and AF (HR=1.33; 95% CI, 1.30-1.37) compared with those without obesity and who were metabolically healthy. Conversely, the risk was not higher for MI (HR=0.92, 95% CI, 0.87-0.98), ischemic stroke (HR=0.93, 95% CI, 0.88-0.98), or CV death (HR=0.99; 95% CI, 0.93-1.04), according to the study.

Results also showed that men with MHO had a higher risk of clinical events compared with metabolically healthy men of normal weight (HR, 1.12-1.8), while women with MHO had a lower risk for most events than metabolically healthy women of normal weight (HR, 0.49-0.99).

“Our findings suggest that the early detection and management of individuals with obesity may therefore be beneficial in the prevention of AF and of HF, whilst appropriate management of individuals with no obesity and metabolic abnormalities may be beneficial in the prevention of ischaemic events,” concluded study authors.

The authors also noted limitations to their study, including that the results show observational associations rather than cause and effect, study participants were from 1 country with a predominately White population, and they were unable to account for some potential confounders (eg, socioeconomic status, exercise, diet, and metabolic control).

Reference: Fauchier G, Bisson A, Bodin A, et al. Metabolically healthy obesity and cardiovascular events: A nationwide cohort study. Diabetes Obes Metab. 2021;23:2492-2501.