Lifestyle modifications may improve kidney function in patients with NASH

Improved liver histology due to lifestyle modifications was associated with improved renal function among patients with nonalcoholic steatohepatitis, according to published findings.

“The exact mechanism to explain these findings have not yet been entirely elucidated; however, it may be a reflection of the improvement in oxidative stress, insulin sensitivity, inflammation, and vascular endothelial function and permeability that may contribute to positive changes in kidney function,” Naga P. Chalasani, MD, FACG, professor of gastroenterology and hepatology at Indiana University School of Medicine, said in a press release.

Naga P. Chalasani

Chalasani and colleagues conducted a post-hoc analysis of a recent clinical trial that included 293 patients with biopsy-proven NASH who were given the option to undergo lifestyle modifications over a duration of 52 weeks to determine any relationship between changes in renal function and liver histology.

Some 261 participated and were encouraged to receive protocolized lifestyle modifications (less calorie intake, daily exercise) during the clinical trial at the National Institute of Gastroenterology, Havana Cuba between June 2009 and May 2013.

Results showed a one-stage reduction in fibrosis (P < .01) and resolution of NASH (P < .01) were significantly correlated with an improvement in the kidney function. The estimated glomerular filtration rates (eGFR) were significantly increased in patients with fibrosis improvement (+7.6 ± 6.5 mL/min/1.73 m²) compared with patients who did not have fibrosis improvement (−1.98 ± 6.4 mL/min/1.73 m²; P < .01) after 52 weeks.

The resolution of NASH and 1-point improvement in fibrosis was an effect that was independent of baseline kidney function, weight loss and other confounding covariates (P < .05 for both), the researchers wrote.

In addition, resolution of NASH was associated with an increase in eGFR (2.32 ± 7.8 mL/min/1.73 m²) compared with patients without resolution of NASH (−1.04 ± 5.9 mL/min/1.73 m²; P = .04) after 52 weeks.

The researchers note that their results should be interpreted with caution due to various limitations: the full definition of chronic kidney disease was unfulfilled; no renal tissue was available for analysis; they were unable to demonstrate correlations between change in kidney function and physical activity; among others.

“A significant association was found between improvements in histological NASH-related endpoints and changes in renal function, which may suggest attenuation on inflammatory and fibrogenetic processes improving kidney and liver function through lifestyle modifications,” the researchers wrote, adding that it is still unclear if long-term lifestyle modifications in patients with nonalcoholic fatty liver disease with normal or altered kidney function will prevent progression of the renal disease.

They concluded: “As new pharmacologic therapies for NASH are emerging, the planning of clinical trials that aim to verify whether treating NAFLD patients may effectively prevent renal impairment should be considered.” – by Melinda Stevens