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Metabolically healthy obesity confers excess risk for HF, but not acute MI
Obesity in the absence of metabolic abnormalities does not appear to confer substantial risk for acute MI. However, even metabolically healthy obesity appears to be associated with increased risk for HF, particularly long-lasting or severe obesity.
Researchers reported data from a population-based prospective cohort study of participants from the Nord-Trøndelag health study (HUNT; n=61,299) who had no history of acute MI, HF or cerebral stroke at baseline.
Participants were classified by metabolic status and BMI (normal: <25 BMI; overweight: 25-29.9 BMI; obese: ≥30 BMI; severely obese: ≥35 BMI) and followed for a median of 12 years. Participants who had BMI measurements taken in the 1960s, ’80s and ’90s were classified as long-term obese if BMI was ≥30 at all three measurements. Participants were classified as metabolically unhealthy if they had elevated waist circumference (men: >94 cm; women: >80 cm) or BMI ≥30, besides two of the following: elevated non-fasting triglycerides (≥1.7 mmol/L); reduced HDL (men: <1.03 mmol/L; women: <1.29 mmol/L); elevated BP (≥130 mm Hg/80 mm Hg) or use of BP medication; and elevated nonfasting glucose (≥11.1 mmol/L) or a diagnosis of diabetes.
Among all participants, 16.4% were classified as obese, 25.4% metabolically unhealthy, 2,547 had acute MI and 1,201 developed HF, according to Bjørn Mørkedal, MD, PhD, of Norwegian University of Science and Technology, Trondheim, Norway, and colleagues.
The study’s primary endpoints were first incidence of acute MI or HF, as identified by hospital admission records or Norway’s National Cause of Death Registry.
Compared with normal-weight and metabolically healthy participants, those who were obese but metabolically healthy did not have an elevated risk for acute MI (HR=1.1; 95% CI, 0.9-1.4); however, risk was elevated in those who were obese but not metabolically healthy (HR=2; 95% CI, 1.7-2.3). The researchers found that the same dichotomy was true for participants with severe and long-term obesity.
“Risk [for acute MI] among metabolically unhealthy individuals appears to be increased across the whole range of BMI,” the researchers wrote.
Compared with normal-weight and metabolically healthy participants, those who were obese had an elevated risk for HF regardless of metabolic status (metabolically healthy: HR=1.7; 95% CI, 1.3-2.3; metabolically unhealthy: HR=1.7; 95% CI, 1.4-2.2). The HRs were higher in participants with severe or long-term obesity, regardless of metabolic health, Mørkedal and colleagues found.
Disclosure: The researchers report no relevant financial disclosures.