Effects Of Moderate-intensity Exercise On Hepatic Lipids In Older Adults With Prediabetes Mellitus

Objectives:Pre-diabetes mellitus(PDM)carries a high risk of progression to type 2diabetes and poses a high health risk.Ectopic fat deposition in the liver is an important cause of glucose metabolism disorders.And exercise,an important means to reduce liver fat,is less adherent in the elderly.Yijinjing combined with resistance exercise incorporating physical activity,breathing and exhalation,and mental conditioning is particularly beneficial for the elderly,but its effectiveness in preventing the development of diabetes and inhibiting liver fat deposition has rarely been reported.This randomized controlled trial aimed to evaluate the effect of traditional Chinese exercise,Yijinjing combined with resistance exercise,on intrahepatic lipid,body fat distribution,glucolipid metabolism,and inflammatory factors in older adults with pre-diabetes mellitus(PDM).To provide a reference for the application of traditional Chinese exercise in the prevention and control of type 2diabetes and in improving compliance with exercise interventions in older adults.Methods:Thirty-four prediabetic patients aged 50-70 detected in the Department of Endocrinology and Metabolism outpatient clinic,Yangpu District,Shanghai,were randomly divided into exercise and control groups,with 17 subjects in each group.During the trial,3 exercise group members withdrew due to family problems,back pain,and shoulder surgery.Thirty-one subjects completed the study,14 in the exercise group(mean age 63.29±5.51 years;mean weight 70.89±10.26 kg)and 17 in the control group(mean age 61.82±4.33 years;mean weight 69.31±11.17 kg).The exercise group performed moderate-intensity Yijinjing and resistance training five times weekly for six months.Resistance exercises were performed with elastic bands involving muscles that play a significant role in daily life.The exercise intensity was controlled moderately,and the patients felt warm and slightly sweating.The subjects’ maximum heart rate(HRmax)was estimated at 220-age,the expected exercise intensity was 60-70%,and the target heart rate was:(maximum heart rate-resting heart rate)*exercise intensity + resting heart rate.The body composition(body fat distribution and muscle mass)were measured by using dual-energy X-ray absorptiometry;intrahepatic lipid was measured through magnetic resonance imaging;and measured plasma glucose,lipid and insulin metabolism,inflammatory cytokines including plasma silent information regulator 1(SIRT1),NF-κBp65,interleukin-6(IL-6)and tumor necrosis factor α(TNF-α)at baseline and six months.Results:1.After six months,subjects in the exercise group significantly decreased weight,BMI,waist circumference,and hip circumference.The control group significantly decreased waist circumference(P < 0.05).2.The exercise group showed significant reductions in the fat ratio in the upper limbs and thighs after the intervention(P < 0.05),and the fat mass in the upper limbs,thighs,Android area,Gynoid area,and total body fat mass in the exercise group showed a significant decrease(P < 0.05).No significant changes were observed in the control group.In comparison between groups,subjects in the exercise group had significantly lower fat mass in the thighs and Gynoid area than the control group after the intervention(P < 0.05).The control group showed a significant decrease in muscle mass after six months(P = 0.025);the exercise group showed an increasing trend in total body muscle mass,but the differences were insignificant.The amount of change in muscle mass significantly differed between the two groups,with a significant decrease in whole-body muscle mass in the control group(P = 0.027).3.Six months of exercise significantly reduced intrahepatic lipids in the exercise group(9.15 ± 5.00 % vs.7.02 ± 5.11 %,P = 0.008).No significant change was observed in the control group.The amount of change in intrahepatic lipid significantly differed between the exercise and control groups(P < 0.001).4.After the intervention,fasting blood glucose in the exercise group decreased significantly(P = 0.025).2h postprandial blood glucose showed a downward trend,but there was no significant difference between groups(P = 0.720).There were no significant changes in the control group(P > 0.05).The HOMA-IR index in the exercise group was significantly lower than the baseline(3.40±1.39 vs.2.73±1.29,P= 0.025).The HOMA-IR of the control group decreased from 2.91±1.13 before intervention to 2.49±1.17,but the difference was not significant(P = 0.131).Triglyceride in the exercise group was significantly reduced(P = 0.002).There were no significant differences between groups of inflammatory factors SIRT1,NF-κB p65,IL-6,and TNF-α(P > 0.05).5.Changes in intrahepatic lipids were moderately correlated with changes in BMI(R = 0.469,P = 0.008),body fat mass(R = 0.513,P = 0.003),HOMA-IR(R =0.508,P = 0.004),and weakly correlated with changes in total cholesterol(R =0.379,P = 0.035).Conclusions:Yijinjing combined with resistance exercise was effective in reducing body weight,waist circumference,and hip circumference in the elderly PDM patients,accompanied by reductions in hepatic lipid and fat mass in the upper extremities,thighs,Android area,Gynoid area,and whole body.Exercise intervention was effective in improving fasting glucose,HOMA-IR,triglycerides.And the changes in BMI,whole-body fat mass,and HOMA-IR were significantly moderately positively correlated with the changes in hepatic lipids,and the changes in triglycerides were weakly correlated with the changes in liver fat mass.