Objective: A common variant in mitochondrial DNA (mtDNA) at bp 16189 (T C transition) has been associated with small birth size, adulthood hyperglycemia and insulin resistance in Caucasians. In this study we investigated whether mtDNA 16189 variant is associated with metabolic syndrome in Chinese subjects.

Methods: Six hundred fifteen Chinese adults, aged 40 or older, were recruited in this study. The 16189 variant of mtDNA was detected using the PCR and restriction enzyme digestion. Metabolic syndrome was diagnosed on modified NCEP ATP III guidelines, using body mass index (BMI) instead of waist circumference. Association study was performed with ² test and logistic regression analysis.

Results: The prevalence of the 16189 variant was higher in patients with metabolic syndrome than in those without (44%[125/284] vs. 33.2%[110/331], P = 0.006). The association between this 16189 variant of mtDNA and metabolic syndrome (P = 0.021) remained significant even after correcting for age and BMI. As to the individual traits, the prevalence of fasting plasma glucose110 mg/dl (6.1 mmol/L) (51.5%[121/235] vs. 42.1%[160/380], P = 0.023), Type 2 DM (48.1%[113/235] vs. 39.2%[149/380], P = 0.031) and hypertriglyceridemia (44.3%[104/235] vs. 35.8%[136/380], P = 0.037) were significantly higher in subjects harboring the 16189 variant of mtDNA than those with the wild-type. However, the prevalence of hypertension (53.2%[125/235] vs. 47.6%[181/380], P = 0.180), BMI >25 kg/m² (48.5%[114/235] vs. 43.9%[167/380], P = 0.270) and low HDL-cholesterol (61.3%[144/235] vs. 54.7%[208/380], P = 0.111) did not reach a significant difference between the two groups. Furthermore, there was a trend of increasing frequency of occurrence of the 16189 variant in individuals having an increasing number of components of metabolic syndrome (Ptrend <0.005).

Conclusion: Our data strongly suggest that mtDNA 16189 variant underlies susceptibility to metabolic syndrome in Chinese population.