Does the hormone of eternal youth protect against nonalcoholic steatohepatitis?

Circulating adiponectin levels in type 2 diabetes mellitus patients with or without non-alcoholic fatty liver disease: Results of a small, open-label, randomized controlled intervention trial in a subgroup receiving short-term exenatide

AIM

Diabetes mellitus type 2 (DMT2) and non-alcoholic fatty liver disease (NAFLD) are both characterized by decreased circulating adiponectin. Recently, glucagon-like peptide-1 receptor agonists have been shown to induce adiponectin's expression. However, their interaction on clinical grounds needs to be further elucidated.

METHODS

DMT2 patients with abnormal aminotransferases were screened for NAFLD and subjected to liver biopsy (group A, n=17). A subgroup of patients (n=110), after assessed for eligibility criteria, was blindly randomized to receive either 6-month exenatide supplementation on glargine insulin (group B) or intense, self-regulated, insulin therapy alone (group C).

RESULTS

Baseline patient characteristics: 49(38.6%) males, aged 63.1 ± 7.5 years-old, BMI 32.9 ± 4.9 kg/m(2), HbA1c 8.1 ± 1.2% (65 ± 14 mmol/mol), median ALT 23 U/L (range 5-126), AST 20 U/L (7-72). Group A had biopsy-proven NAFLD with a median Activity Score of 5 and fibrosis stage 3. Presence of NAFLD was accompanied by a significant decline in adiponectin (p<0.001), which was negatively correlated with the degree of ALT in all groups (Spearman's correlation, rs=-0.644, p<0.001). In the subgroup intervention trial, adiponectin was significantly raised in both groups B and C (t-Student for paired samples, p=0.001) by Δ=+24.2% (interquartile range 14.8-53.2%). This elevation was not associated with the type of intervention but with weight loss, glycemic control and reduction of C-reactive protein (one-way ANCOVA).

CONCLUSION

Supplementation of exenatide to glargine insulin compared to standard insulin was: (i) effective in inducing weight loss, (ii) non-inferior in lowering HbA1c and (iii) non-inferior in increasing circulating adiponectin. Higher adiponectin was associated with lower ALT, suggesting a hepato-protective role for this cytokine.

Lower circulating levels of dehydroepiandrosterone, independent of insulin resistance, is an important determinant of severity of non-alcoholic steatohepatitis in Japanese patients

AIM

  The biological basis of variability in histological progression of non-alcoholic fatty liver disease (NAFLD) remains unknown. Dehydroepiandrosterone (DHEA), the most abundant steroid hormone, has been shown to influence sensitivity to reactive oxygen species, insulin sensitivity and expression of peroxisome proliferator-activated receptor-α. Our aim was to determine whether more histologically advanced NAFLD is associated with low circulating levels of DHEA in Japanese patients.

METHODS

  Serum samples were obtained in 133 Japanese patients with biopsy-proven NAFLD and in 399 sex- and age-matched healthy people undergoing health checkups. Serum levels of sulfated DHEA (DHEA-S) were measured by chemiluminescent enzyme immunoassay.

RESULTS

  Serum DHEA-S levels in NAFLD patients were similar to those in the control group. Of 133 patients, 90 patients were diagnosed as non-alcoholic steatohepatitis (NASH): 73 patients had stage 0-2, and 17 had stage 3 or 4. Patients with advanced NAFLD (NASH with fibrosis stage 3 or 4) had lower plasma levels of DHEA-S than patients with mild NAFLD (simple steatosis or NASH with fibrosis stage 0-2). The area under the receiver operating characteristic curve for DHEA in separating patients with and without advanced fibrosis was 0.788. A "dose effect" of lower DHEA-S and incremental fibrosis stage was observed with a mean DHEA-S of 170.4 ± 129.2, 137.6 ± 110.5, 96.2 ± 79.3, 61.2 ± 46.3 and 30.0 ± 32.0 µg/dL for fibrosis stages 0, 1, 2, 3, and 4, respectively. The association between DHEA-S and severity of NAFLD persisted after adjusting for age, sex and insulin resistance.

CONCLUSION

  Low circulating DHEA-S might have a role in the development of advanced NASH.