Obesity, Metabolically Benign

Evidence of the effects of metabolically healthy obesity (MHO) on atherosclerosis is limited; the transition effects of metabolic health and obesity phenotypes have been ignored. We examined the association between metabolic health and the transition to atherosclerosis risk across body mass index (BMI) categories in a community population.

This cross-sectional study was based on a national representative survey that included 50,885 community participants aged ≥40 years. It was conducted from 01 December 2017 to 31 December 2020, in 13 urban and 13 rural regions across Hunan China. Metabolic health was defined as meeting less than three abnormalities in blood pressure, glucose, high-density lipoprotein cholesterol, triglycerides, or waist circumference. The participants were cross-classified at baseline based on their metabolic health and obesity. In addition, the relationship between atherosclerosis and transitions in metabolic health status based on 4733 participants from baseline to the second survey after 2 years was considered. The relationship between metabolic health status and the risk of transition to Carotid atherosclerosis (CA) was assessed using logistic regression and Cox proportional hazards regression analyses.

In this study, the mean age of the participants was 60.7 years (standard deviation [SD], 10.91), 53.0% were female, and 51.2% had CA. As compared with metabolically healthy normal weight (MHN), those with MHO phenotype (odd ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.21), metabolically unhealthy normal weight (OR 1.27, 95% CI 1.19-1.35), metabolically unhealthy overweight (OR 1.41, 95% CI 1.33-1.48), and metabolically unhealthy obese (OR 1.54, 95% CI 1.44-1.64) had higher risk for CA. However, during the follow-up of 2 years, almost 33% of the participants transitioned to a metabolically unhealthy status. As compared with stable healthy normal weight, transition from metabolically healthy to unhealthy status (hazard ratios [HR] 1.21, 95% [CI] 1.02-1.43) and stable metabolically unhealthy overweight or obesity (MUOO) (HR 1.32, 95% CI 1.17-1.48) were associated with higher risk of CA.

In the community population, obesity remains a risk factor for CA despite metabolic health. However, the risks were highest for metabolically unhealthy status across all BMI categories. A large proportion of metabolically healthy overweight or participants with obesity converts to an unhealthy phenotype over time, which is associated with an increased risk of CA.

Obesity is considered a major growing threat to public health which could negatively affect the quality of life. The current cross-sectional study was conducted to investigate the population-based prevalence of metabolically healthy obesity (MHO) and healthy overweight (MHOW) and associated factors in southern Iran.

Baseline data from the Pars Cohort Study was analyzed. Metabolically healthy participants were identified based on the definition of the American Heart Association for the metabolic syndrome. The prevalence of MHOW and MHO and their 95% confidence intervals were estimated. Poisson regression was applied for the calculation of prevalence ratios (PRs).

Gender- and age-standardized prevalences of MHOW and MHO were 6.3% (6.0%-6.6%) and 2.3% (2.1%-2.5%), respectively. The following factors were associated with being MHOW compared with those with normal weight: Being younger, female gender (1.31, 1.20-1.43), higher socioeconomic status, being noncurrent cigarette smoker (1.27, 1.11-1.45), low level of physical activity (1.14, 1.03-1.25), having normal overweight during adolescence, and overweight (1.35, 1.24-1.48) or obesity (1.68, 1.53-1.86) during young adulthood. We also found strong associations between MHO and younger age groups, female gender (2.87, 2.40-3.42), being married (1.57, 1.08-2.27), Fars ethnicity (1.25, 1.10-1.43), higher socioeconomic status, ever use of tobacco (1.14, 1.00-1.30), never use of opium (1.85, 1.19-2.86), lower physical activity (1.45, 1.20-1.72), being normal weight in 15-year body pictogram and being overweight (1.87, 1.59-2.20) or obese (3.20, 2.74-3.72) in 30-year body pictogram when considering those with normal weight or MHO.

Potentially modifiable factors including physical activity should be more emphasized. Furthermore, our study issued that it would be more reasonable that the prevention of unhealthy obesity be initiated before the development of MHO, where there are more protective factors and they could be more effective.

We aimed to investigate the independent and joint associations between metabolic status, PA (physical activity) and risk of CVD (cardiovascular disease) in participants with obesity.

We included 109,301 adults with obesity free of baseline CVD enrolled from 2006 to 2010 in the UK Biobank cohort (aged 56 ± 7.9 years). Based on metabolic status, obesity was grouped into metabolically healthy obesity (MHO; free of hypertension, hypercholesterolemia and diabetes; n = 26,989; BMI 33 ± 3.3 kg/m²) and metabolically unhealthy obesity (MUO; n = 82,312; BMI 34 ± 4.0 kg/m²). PA was categorized into four groups according to moderate-to-vigorous PA (MVPA): none, low, medium, and high. Multivariable Cox regression models were used for the main analyses adjusting for sociodemographic factors, lifestyles and comorbidities.

There were 8,059 CVD events during a median follow-up of 8.1 years. MHO was associated with a 42% reduced risk of CVD compared with MUO (HR = 0.58, 95% CI: 0.53-0.63). A significant interaction effect between PA and metabolic status on CVD risk was found. Among MUO participants, individuals with PA had significantly decreased CVD risk when compared with no MVPA (HR = 0.87, 95% CI: 0.81-0.94 for low PA; HR = 0.85, 95% CI: 0.78-0.93 for medium PA; and HR = 0.86, 95% CI: 0.80-0.92 for high PA). The lowest CVD risk was observed in MHO & medium PA group when compared with MUO & no MVPA (HR = 0.45, 95% CI: 0.37-0.56).

Both MHO and any MVPA were associated with reduced risk of CVD in adults with obesity, while PA could modify the relationship between metabolic status and CVD risk.