Metabolically healthy obese and unhealthy normal weight in Iranian adult population: Prevalence and the associated factors.

AIMS: The objective of this study was to determine the prevalence and the associated factors of metabolically unhealthy in normal-weight and metabolically healthy in obese.

METHODS: We analyzed the data of a representative sample of 986 participants recruited among adult population of north of Iran. Data were collected regarding demographic characteristics, lifestyle, body mass index, abdominal obesity measures, blood pressure, and lipid profiles. The participants were classified as metabolically healthy obese (MHO) and metabolically unhealthy normal-weight (MUNW). Metabolically unhealthy was defined as the presence of  ≥2 non-obese components of metabolic syndrome based on ATP III criteria.

RESULTS: The prevalence rate of MUNW and MHO accounted for 17.2% and 15.1% respectively. Mean age of participants with metabolically unhealthy was significantly greater than metabolically healthy in both normal weight and overweight/obese (P=0.001). The results of multiple logistic regression analysis showed in normal-weight individuals, a significant association of MUNW was found with age group of 50-59 years(OR=3.83, 95%CI: 1.71-8.57) and 60-70 years by OR=4.74(95%CI:1.79-12.54) as compared with age group of 20-29 years. It was also associated with current smoking. While metabolically healthy state in overweight/obese was inversely associated with age 50-59 years by OR=0.26 (95%CI:0.13-0.54) and age 60-70 years by OR=0.15 (95%CI:0.05- 0.39) and higher WC by OR=0.47 (95%CI:0.31-0.72) but positively associated with female-sex by OR=1.74 (95%CI:1.07-2.82).

CONCLUSION: Aging and smoking are significantly associated with metabolic abnormalities in normal-weight while aging, abdominal obesity negatively and female positively associated with metabolically healthy in obese.