Weight gain since age of 20 as risk of metabolic syndrome even in non-overweight individuals

Metabolic syndrome (MetS), regardless of the presence of obesity, is known as a risk of diabetes and cardiovascular disease. Weight gain after age 20 reported to be associated with these diseases. Impact of the difference between the body mass index (BMI) at examination and BMI at age 20 (Delta BMIexa-20y) on MetS, especially in non-overweight individuals, remains to be elucidated. We analyzed the data of 24,363 individuals (14,301 men and 10,062 women) in this cross-sectional study. The diagnosis of MetS was diagnosed when three or more of the following criteria were present: hypertension, hyperglycemia, hypertriglyceridemia, low HDL-cholesterol level, and abdominal obesity. Logistic regression was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for age, alcohol, smoking, exercise, and BMI at examination. Compared to the lowest Delta BMIexa-20y tertile (Delta BMIexa-20y < 1.2 kg/m(2) in men and 0 kg/m(2) in women), the highest tertile (Delta BMIexa-20y 3.2 kg/m(2) in men and 2.0 kg/m(2) in women) was associated with the risk of the presence of MetS (multivariate OR = 1.80, 95%CI 1.53-2.11, p < 0.001 in men and OR = 3.27, 95%CI 2.22-4.96, p < 0.001 in women). This result was also applicable in non-overweight individuals (multivariate OR = 2.06, 95%CI 1.46-2.92, p < 0.001 in men and OR = 2.49, 95%CI 1.40-4.64, p < 0.001 in women). Our analyses showed that Delta BMIexa-20y is associated with the risk of the presence of MetS, even in non-overweight individuals. It is thus important to check weight changes from early adulthood, even in non-overweight individuals.