Effect of soy protein supplementation in patients with chronic hepatitis C:A randomized clinical trial

AIM:To evaluate the effects of soy supplementation on insulin resistance,fatty liver and alanine aminotransferase(ALT) levels in non-diabetic patients with chronic hepatitis C(CHC).METHODS:In a prospective,randomized and singleblinded clinical trial,we compared patients with CHC who had casein as a supplement(n = 80)(control group),with patients who consumed a soy supplement diet(n = 80) [intervention group(IG)].Both groups received 32 g/d of protein for 12 wk.RESULTS:Patients' baseline features showed that 48.1% were overweight,43.7% had abdominal fat accumulation,34.7% had hepatic steatosis and 36.3% had an homeostasis model assessment index of insulin resistance(HOMA-IR) ≥ 3.0.Descriptive analysis showed that protein supplementation diet reduced hepatic steatosis in both groups;however,significant reductions in ALT levels occurred in the soy group.Multiple regression modeling indicated that in the presence of severe fibrosis(F3/F4),g glutamyl transferase elevation and high density lipoprotein(HDL) reduction,the intervention group had 75% less chance of developing hepatic steatosis(OR= 0.25;95% CI:0.06-0.82) and 55% less chance of presenting with an ALT level ≥ 1.5 × the upper limit of normal(ULN)(OR = 0.45,95% CI:0.22-0.89).Soy treatment did not have any effect on insulin resistance(OR = 1.92;95% CI:0.80-4.83),which might be attributed to the fact that the HOMAIR values at baseline in most of our patients were in the normal range.Advanced hepatic fibrosis,an ALT level > 1.5 × ULN and visceral fat were predictors of an HOMA-IR ≥ 3.The IG group had a reduced risk of an ALT level > 1.5 × ULN.An HOMA-IR ≥ 3.0 and HDL < 35 mg/dL were also risk factors for increased ALT.CONCLUSION:Soy supplementation decreased ALT levels and thus may improve liver inflammation in hepatitis C virus(HCV) patients;it also reduced hepatic steatosis in a subgroup of patients but did not change insulin resistance.It should be considered in the nutritional care of HCV patients.