One hundred and forty-four patients with NAFLD associated with mixed dyslipidemia were studied as outpatients in the Tonggji Hospital, Tongji University, from September 2006 to June 2008. Written informed consent was obtained from all patients and the study was approved by the Ethics Committee in Tonggji Hospital of Tongji University.

The inclusion criteria were as follows: age between 18 and 65 years, lack of excessive alcohol ingestion confirmed by careful questioning by the primary physician and dietitians (consumption of less than 70 g alcohol in female and 140 g in male per week), elevated serum alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above the normal limit, but under 5 times the upper limit of the normal range for ≥ 6 mo before the study. Diagnosis of dyslipidemia was based on the presence of one or more of the following findings: fasting serum total cholesterol (TCHO) > 5.7 mmol/L, serum triglyceride (TG) > 1.8 mmol/L and high-density lipoprotein cholesterol (HDL-C) < 0.8 mmol/L, fatty liver diagnosed by abdominal ultrasonography, and ability to give informed consent. Exclusion criteria included overuse of alcohol, viral hepatitis, hemochromatosis, Wilson’s disease, autoimmune hepatitis, α-1 antitrypsin deficiency, primary sclerosing cholangitis or primary biliary cirrhosis; history of any other hepatic, gastrointestinal, renal, cardiovascular, neurological or hematological disorders, psychiatric disorder which might impair the ability of patients to provide written informed consent; as well as pregnancy, breastfeeding, or lack of effective birth control in women at child-bearing age. In addition, patients were excluded if they were on any medications that could influence liver function during the observation period or involved in any clinical trial before the study.

All the patients meeting the criteria for enrollment agreed to participate in the study. The patients were randomized into two groups to receive a 24-wk treatment. Group A (n = 72) received recommended diet and 2 g n-3 PUFA from seal oils (Shanghai Hengsheng Biology & Medicine CO. Ltd, Shanghai, China), three times a day. Group B (n = 72) received recommended diet and 2 g placebo (Shanghai Hengsheng Biology & Medicine CO. Ltd, Shanghai, China), three times a day. Recommended diet was composed of 50% carbohydrates, 20% protein and 30% fat in accordance with the American Heart Association diet[9]. All obese and overweight patients were advised to lose their weight with a restriction of daily caloric intake to 25-30 kcal/kg per day[9]. All medications the patients received during the 24-wk treatment period were recorded. At the time of enrolment and when the study was completed, body temperature, body mass index (BMI), blood pressure and heart rate were detected and liver ultrasonography was performed. Laboratory tests included serum ALT, AST, γ-glutamyltranspeptidase (GGT), TG, TCHO, HDL-C, LDL-C, FBS, and complete blood cell counts.

During the 24-wk treatment period, total symptom scores, liver enzymes and fasting lipids were monitored at weeks 8, 12, 16, and 24. Hepatic fat infiltration was detected by upper abdominal ultrasonography at weeks 12 and 24. Symptoms included liver discomfort or pain, weakness, abdominal distention, and nausea. The severity of each clinical symptom was scored using a 4-point scale as follows: 0 score = asymptomatic, 1 score = mild, 2 scores = moderate, 3 scores = severe. All patients were investigated after 12 h fasting and underwent ultrasonography for liver steatosis. Ultrasound scans were performed by a trained operator who was blind to the treatment of participants. The severity of steatosis was also scored using a 4-point scale as follows[10]: grade 0 = normal echogenicity, grade 1 = slight, grade 2 = moderate, grade 3 = severe.

The data were presented as mean ± SD and analyzed using SPSS11.5 for Windows (SPSS, Chicago, IL, USA). Statistical analysis for baseline characteristics of the study groups was performed using χ² test and t-test. Student’s t-test and Wilcoxon signed rank test were used to evaluate the changes in biochemical parameters before and after treatment. P < 0.05 was considered statistically significant.

Of the 144 patients enrolled in this study, 134 completed the protocol and were included in the analysis. The baseline clinical and demographic data about the two groups are shown in Table 1. Patients in the two groups were matched for age, sex, body height and weight, BMI, HR, course of disease, blood pressure, and blood tests including transaminase and lipid concentrations. The ultrasound stages of steatosis were also paired (P = 0.63). No patient was classified as grade 0. In group A, 37% of the patients were classified as grade1, 48% as grade 2, and 15% as grade 3, respectively. In group B, 30% of the patients were classified as grade 1, 56% as grade 2, and 14% as grade 3, respectively.

No significant difference was observed in dietary compliance, BMI, blood pressure, HR, HB, RBC, WBC, platelet, serum BUN and creatinine(Cr) between the two groups. At the end of a 24-wk treatment period, a significant improvement in several liver and lipid parameters was observed between the two groups. In particular, total symptom scores, ALT and TG levels decreased more significantly (P < 0.01) in Group A (total symptom score = 1.87 ± 1.18 to 0.42 ± 0.72, ALT = 62.79 ± 35.92 U/L to 39.27 ± 18.94 U/L, TG= 3.94 ± 2.69 mmol/L to 2.08 ± 1.03 mmol/L) than in Group B (total symptom score = 1.87 ± 1.18 to 0.42 ± 0.72, ALT = 79.76 ± 50.59U/L to 42.32 ± 22.23U/L, TG = 3.80 ± 2.85 mmol/L to 2.33 ± 1.42 mmol/L) (Table 2). As compared to the pretreatment values, total symptom score, ALT and TG levels at weeks 8, 12, and 16 decreased significantly in the two groups after treatment (P < 0.01).

As expected, there was a tendency toward improvement in AST, GGT, TCHO, and HDL levels (P < 0.05) in the two groups after treatment. However, no significant difference was observed in the two groups. Significant improvements were found in serum LDL-C levels of group A (P < 0.05), but not found in group B after treatment.

Ultrasonography showed a normal liver echopattern at the end of treatment in 19.70% (13/66) of the patients, and an overall reduction in 53.03% (35/66) of the patients in group A. In contrast, only five patients (7.35%, 5/68) achieved complete regression (P = 0.04), whereas 24 patients (35.29%, 24/68) had a certain reduction (P = 0.04) in group B. No change was observed in the remaining 64.71% of patients.

Gastrointestinal complaints of increased fecal frequency, epigastria, and defecation were occasionally noted in 8 of the 134 patients; but these adverse effects were not significantly different in the two groups. The patients recovered when they completed the treatment. Most of the patients who completed the treatment had no adverse events, indicating that they can tolerate the treatment. No severe adverse event was observed.

Recent reports suggest that many cases of cryptogenic liver cirrhosis may be related to unrecognized nonalcoholic steatohepatitis (NASH); however, medical therapy for nonalcoholic fatty liver disease (NAFLD) and NASH has been disappointing to date. The only recommended therapies are dietary modification and weight loss. N-3 polyunsaturated fatty acids (PUFA) seems to be efficacious on treating NAFLD from animal and some small samples human studies.

The present “gold standard” for treatment of NAFLD is a reduction in central obesity so as to reverse insulin resistance. Several small samples randomized trails have suggested n-3 PUFA from different animals were effective in the treatment of NAFLD; we explored whether seal oil is efficacious and safe in large samples NAFLD patients.

Total symptom scores in NAFLD patients, and large samples were observed besides biochemical indicators and ultrasonography in this study. Seal oils n-3 PUFA can improve liver enzyme, serum lipid levels and normalization of ultrasonographic evidence.

Seal oils PUFA administration seems to be safe and efficacious for patients with NAFLD associated with hyperlipidemia as well as the “lifestyle adjustment” or anti-obesity measures.

NAFLD refers to the presence of hepatic steatosis not associated with a significant intake of ethanol. Insulin resistance is central to the pathogenesis of NAFLD; thus obesity, diabetes, and the metabolic syndrome are frequently associated with the disease.

This is an interesting study. Further details need to be given as to the precise ultrasound scoring system that was used to assess the resolution of hepatic steatosis. Was there an objective scoring system used or was this all subjective? The paper is otherwise well written and merits publication.