The impact of obstructive sleep apnea hypopnea syndrome on nonalcoholic fatty liver disease in the nonobese elderly / 中华老年医学杂志

ABSTRACT

Objective To investigate the impact of obstructive sleep apnea hypopnea syndrome (OSAHS) on development of nonalcoholic fatty liver disease (NAFLD) in the non-obese elderly.Methods A total of 91 non-obese elderly patients were divided into 3 groups,29 cases with mild to moderate SAHS (mild-to-moderate OSAHS group),31 cases with severe OSAHS (severe OSAHS group),30 cases without OSAHS and matched with age,sex and BMI (control group).The changes in NAFLD severity index including serum liver enzyme levels,Type Ⅲ procollagen peptide (PⅢ P)and liver/spleen CT ratio were observed,and the influence factors for the changes were analyzed.Results Serum alanine aminotransferase (ALT),aspartate aminotransferase (AST)ALT/AST ratio and serum PⅢ P levels were significantly higher in severe OSAHS group than in mild-to-moderate OSAHS and the control group(F=25.71,15.15,18.64,respectively,all P＜0.01).There was no significant differences in serum liver enzyme ALT,AST and P Ⅲ P levels between mild-to-moderate OSAHS and the control groups(all P＞0.05),and the ALT/AST ratio was significantly higher in mild-to-moderate OSAHS group than in the control group(P＜0.01).The Liver/spleen CT ratio was significantly lower in OSAHS groups than in control group,while the ratio was lower in severe OSAHS group than in mild-to-moderate OSAHS group(all P＜0.01 or 0.001).Serum PⅢ P level was significantly higher in OSAHS groups than in control group(F=31.46,P＜0.01),while PlⅢ P levels were not significantly different between the mild-to-moderate OSAHS group and the control group(P ＞ 0.05).The correlation analysis showed that the liver/spleen CT ratio in OSAHS group was negatively correlated with AHI(r=-0.785,P＜0.001),but was positively correlated with the lowest oxygen saturation(r=0.517,P=0.001).The ALT/AST ratio and serum P Ⅲ P level in OSAHS patients were positively correlated with AHI (r=0.463,0.770,both P＜0.001),but were negatively correlated with the lowest oxygen saturation (r=-0.395,-0.514,P＜0.01 or 0.001).The multiple regression analysis showed that AHI was the only variable that affected liver/spleen CT ratio and serum P Ⅲ P level in OSAHS patients.Conclusions OSAHS patients in the non-obese elderly are always complicated with NAFLD,characterized by abnormal liver enzymes,hepatic steatosis and fibrosis.The severity of lesion is increased with the deterioration of OSAHS.AHI may play an important role in the development of NAFLD in the non-obese elderly with OSAHS.