Individual and joint associations of obesity and metabolic health parameters on arterial stiffness: Evidence from the UK Biobank.

Aims: There is conflicting evidence regarding whether excess adiposity without metabolic abnormalities reflects a truly benign phenotype. This study evaluated the independent and joint associations of the presence of excess adiposity and metabolic abnormalities on arterial stiffness.

Materials And Methods: Participants in UK Biobank with body mass index (BMI) and arterial stiffness index (ASI) recorded between 2006 and 2010, free from cardiovascular diseases and not underweight (BMI <18.5 kg/m) were included. The primary outcome was severity of ASI analysed using multivariate-adjusted linear regression.

Results: Of 162 590 participants, 42.5% were overweight and 24.4% were obese. Within the normal BMI strata, 50.7% had ≥1 metabolic abnormality. Compared to individuals with normal BMI and no metabolic abnormality (reference group), increased BMI or metabolic abnormalities were similarly associated with higher ASI: normal BMI with metabolic abnormalities (adjusted β-coefficient and 95% CI, 0.35; 0.30-0.40); overweight without metabolic abnormalities (0.32; 0.26-0.37). Individuals with obesity and no metabolic abnormality had higher ASI (0.65; 0.57-0.74) but was lower than individuals with overweight and metabolic abnormalities (0.80; 0.75-0.84). Individuals with obesity and metabolic abnormalities had the highest ASI (1.07; 1.02-1.12) among all six metabolic combinations, p < 0.001 for each versus reference group. Sensitivity analysis suggested higher ASI with increasing number of metabolic abnormalities within BMI categories and higher ASI in the presence of abdominal obesity within metabolic categories.

Conclusions: Excess adiposity and metabolic abnormalities are independently associated with increased arterial stiffness to a similar degree, suggesting that metabolically healthy individuals with overweight and obesity are not benign groups. This reinforces the need to prevent excess adiposity and consider primary prevention strategies even before metabolic abnormalities emerge.