This RCT demonstrated the benefits of both normoglucidic low-calorie and low-fat diets in individuals with CHC. Our results indicated that after 1 year, overweight and obese patients with CHC had similar weight reduction with both diets. The dropout rate in LFD was significantly greater than that in NGLCD. Similar to prior studies, we observed a faster weight loss after initiation of a NGLCD and equivalent weight loss after 1 year [26
This study demonstrated that lifestyle changes (NGLCD or LFD and physical activity) improved the anthropometric parameters, glucose parameters and lipid and liver profiles. Further improvement was noted in the results of non-invasive liver fibrosis testing, as well as improvement of the prevalence and severity of hepatic steatosis.
The prevalence of MetS in our study was higher than previously published in Romania [27
] and in Europe, most likely because we included overweight patients (BMI over 25 kg/m2). At baseline 61.5% of patients belonging to the NGLCD group and 61.5% to the LFD group presented MetS. In the largest retrospective survey (239 HCV-positive subjects) 16.7% had metabolic syndrome [28
]. In other studies [29
], the prevalence of metabolic syndrome in chronic HCV-infected patients ranged from 4.1 to 44% [31
Even the weight loss at 12 months wasn’t spectacular (−3.9 [95% CI −4.8, -3.1]kg in NGLCD vs. −3.1 [95% CI −3.8, -2.3]kg in LFD) there was a reduction in MetS prevalence (25.9% in NGLCD group and 26.9% in LFD group). In CHC patients lifestyle changes through medical nutritional therapy and physical activity led to an improvement in all metabolic parameters: reduced insulin resistance, lower blood glucose, lower triglycerides, total serum cholesterol, LDL-C, increased HDL-C, reducing systolic and diastolic blood pressure.
Modest weight loss of 5–10% body weight is known to reduce insulin resistance in obese individuals [32
In our study a normoglucidic low-calorie diet (with limited refined carbohydrates and sugar intake, and increased fruits, vegetables and whole grains intake) was accompanied by improvement in insulin resistance (HOMA-IR) lipid and liver profile.
The metabolic changes induced by the low-fat, high carbohydrate, high protein diet were associated with similar weight losses, improved lipid and glucose profiles, however there were no adverse changes in renal function parameters but the compliance to this diet was lower (drop out rate was almost double).
Thus, even if macronutrient intake was different, there were similar improvements in glycemia and insulin resistance, indicating that in the context of tolerable diets and weight loss, mild variations in nutrient fuels have limited impact on glucose metabolism.
In overweight/obese patients with steatosis who subsequently lost weight, liver-related abnormalities improved [33
]. Although weight loss may be difficult to achieve and sustain, the patients who did manage to lose weight showed a reduction in steatosis and abnormal liver enzymes as well as improvement in liver fibrosis, despite the persistence of the virus [34
]. Lifestyle changes are deemed to be additive to proper antiviral treatment schedules, which remain the standard of care [31
The effects of lifestyle changes on hepatic inflammation and fibrosis varied [35
], only one study showed significant improvement [36
In patients with steatosis, lifestyle changes (diet and exercise) were associated with improvement of ALT levels [35
] and steatosis [35
Recently a semiquantitative index used to assess steatosis was validated against histology [37
] and proved useful in the specific setting of lifestyle interventions [38
Limitations of the study are: we used non-invasive methods to estimate steatosis and fibrosis in patients with CHC, and these indices are less sensitive and specific in these patients; the analysis and presentation of only detailed food journals may bias the estimate of food intake; recruited patients were overweight (BMI
) thus the prevalence of MetS was higher.
At this point only lifestyle interventions can be recommended to improve metabolic syndrome and obesity associated with chronic hepatitis C, but their effect on treatment response and long term outcome requires further study.
Moderate exercise is recommended for all persons with hepatitis C who did not experience advanced cirrhosis or other metabolic complications [17
]. In the present study, changes in food intake and the increase of physical activity were sustainable, associated with long-term metabolic benefits. In some studies, patients with CHC who participated in light or moderate exercise programs reported an improvement in some symptoms such as nausea, fatigue, depression and appetite [17
An important issue related to long-term of dietary interventions is that adherence decreases over time and therefore achieving the treatment goals involves an individualized education program, structured and continuously adapted to the socio-biological and family environment, with patient’s involvement in his own treatment.
Long-term benefits can be confirmed only by large studies over a longer period of time, where the patient has adopted the habit of an optimal lifestyle.