The current study investigated the association between PLIN polymorphisms and the combination of hypertension and obesity (HO) and the related clinical features. The polymorphisms 1237 (T/C), 1243 (C/T), and 1323 (C/G) were genotyped in 503 cases with HO and 511 unrelated controls. No associations between polymorphism 1237 (T/C) or 1243 (C/T) and HO were found. However, total cholesterol (TC) levels were significantly different among genotypes of polymorphism 1243 (p = 0.023, power = 0.55). In male cases, 1243T carriers (TT + CT) had higher TC, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol levels compared with CC homozygote carriers (5.23 +/- 0.88 vs. 4.98 +/- 0.90, p = 0.024; 1.13 +/- 0.23 vs. 1.07 +/- 0.22 mM, p = 0.034; 3.3 +/- 0.78 vs. 3.11 +/- 0.80, p = 0.03, respectively). Additionally, 1243T allele carriers were more prevalent among the subjects with both HO and elevated TC levels (> or =5.2 mM) than those with HO and optimal TC levels (<5.2 mM) (chi(2) = 8.53; p < 0.003; odds ratio, 1.69; 95% confidence interval, 1.19 approximately 2.42). Multiple logistic regression analysis suggested a significant contribution of polymorphism 1243 to the elevated TC levels after controlling for conventional risk factors (odds ratio, 1.48; 95% confidence interval, 1.14 approximately 1.91; p = 0.003). Polymorphism 1243 in the PLIN gene did not seem to be associated with HO but with TC levels in Chinese. The PLIN gene may be involved in human lipid metabolism.