Niacin reduces plasma
triglycerides, but it may increase
free fatty acids and
insulin resistance during long-term treatment. We examined the effect of extended-release
niacin on liver fat content in Chinese patients with
dyslipidemia and whether the common
diacylglycerol acyltransferase-2 (DGAT2) polymorphisms influenced this effect. The 39 patients (baseline liver fat content: 12.8 ± 7.6%,
triglycerides: 3.30 ± 1.67 mmol/l) were treated with
niacin, gradually increasing the dose to 2 g/day for a total of 23 weeks. The liver fat content and visceral/subcutaneous fat was measured before and
after treatment. Subjects were genotyped for the DGAT2 rs3060 and rs101899116 polymorphisms. There were significant (P < 0.001) reductions in plasma
triglycerides (-34.9 ± 37.6%), liver fat content (-47.2 ± 32.8%), and visceral fat (-6.3 ± 15.8%, P < 0.05) after
niacin treatment. Mean
body weight decreased by 1.46 ± 2.7% (1.17 ± 2.44 kg, P < 0.001) during the study, but liver fat changes remained significant after adjustment for age, gender, and
body weight changes [mean absolute change (95% CI): -6.1% (-8.0, -4.3), P < 0.001]. The DGAT2 variant alleles were associated with a smaller reduction in liver fat content in response to
niacin after adjustment for other covariates (P < 0.01). These findings suggest that
niacin treatment may reduce liver fat content in Chinese patients with
dyslipidemia and that the mechanism may involve inhibition of DGAT2. However, the findings might have been confounded by the small but significant reductions in
body weight during the study. Future large randomized controlled trials are needed to verify these findings.