Study On Influencing Factors Of Resting Energy Expenditure And Respiratory Quotient Of Patients With Newly Diagnosed Type 2 Diabetes Mellitus

ObjectiveThe purpose of this study was to determine influencing factors of resting energy expenditure and respiratory quotient in patients with new diagnosed type 2 diabetes mellitus, and to explore causes and effect of them. So we can make better use of the result of REE and RQ test on nutritional therapy.MethodsA total of 89 outpatients with new diagnosed type 2 diabetes mellitus, who met diagnostic criteria of WHO in 1999 and had never taken any medicine or insulin for lowering blood sugar, were collected from January,2010 to February,2011. REE, RQ, protein, fat and carbohydrate oxidation were tested by indirect calorimetry. And FMM, FM and PBF were measured by using body composition analyzer. We also take anthropometric measurements, serological test and dietary survey. All the results were analyzed by cross-sectional study to investigate influencing factors of resting energy expenditure and respiratory quotient.Results1. Basic data(1) Body composition analysisThe value of height, body weight and fat free mass in male is higher than that in female (P=0.000), while percent body fat and arm lean/ideal lean in female are higher than those in male (P=0.000). Arm lean/ideal lean is higher than leg lean/ideal lean in both male and female. The differences on FFM and VFA between each age group are statistically significant (P=0.001). There is no significant difference between body composition of each group that is divided by the level of plasma glucose (P>0.05).(2) Anthropometric measurementsThe value of waist circumference, waist-hip ratio, arm muscle circumference and grip strength is higher than that of female, and the differences are statistically significant (P＜0.05), while no significant difference can be observed between each group that is divided by the level of age or plasma glucose (P>0.05).(3) The serum markers There are no significant differences on serum markers between each group divided by gender, age or level of fasting plasma glucose.(4) Dietary surveyMean of total diet calories decreased by 750 kcal/day, protein of total diet calories increased by 1.64%, carbohydrate of total diet calories decreased by 2.37%, and the differences are statistically significant (P<0.05),but the difference on fat of total diet calories is no statistically significant (P>0.05).2. Influencing factors of resting energy expenditure(1) Comparison of measured REE and predicted value calculated via H-B equationmeasured REE is 15.60% more than predicted value on average.(2) Co variance analysis of influencing factorsSignificant difference was observed on REE between male and female when analyzing via two independent sample t-test (P=0.000). And the value in male is higher than that in female. But there is no significant difference when analyzing via covariance analysis with fat free mass as covariant (P=0.437). No significant difference can be observed on REE among each group divided by age when analyzing via ANOVA (P=0.075), while statistical difference can be observed when analyzing via covariance analysis with fat free mass as covariant (P=0.047), and young group is higher. There is no significant difference on REE among each group divided by plasma glucose via ANOVA. But statistical difference can be observed when analyzing via covariance analysis with fat free mass as covariant (P=0.000).(3) Multiple linear regression of influencing factorsIt shows that the free fat mass, C-reactive protein and total diet calories after final diagnosis are influencing factors for REE (P=0.000, P=0.005, P=0.046).3. Influencing factors of respiratory quotient(1) Comparison of tested RQ and normal valueMeasured RQ is lower than RQ of normal people who take mixed food, and the difference is statistically significant (P=0.000).(2) The effect of level of blood sugar on RQNo significant differences on RQ and npRQ can be observed among each group with different level of plasma glucose. But the difference on protein oxidation and urinary nitrogen in 24 hours are significant (P=0.015, P=0.032). And a maximum value is obtained when plasma glucose is between 8mmol/L and 10.1mmol/L.(3) The effect of diet on RQFat and carbohydrate of total diet calories after final diagnosis are associated with RQ (P=0.012, P=0.014). The higher fat of total diet calories is, the lower RQ is observed. On contrary, the higher carbohydrate of total diet calories is, the higher RQ is observed. A positive correlation is found between fat of total diet calories and fat oxidation (r=0.243, P=0.022), while a negative correlation is found between fat of total diet calories and carbohydrate oxidation (r=-0.258,P=0.015); A negative correlation is found between carbohydrate of total diet calories and fat oxidation (r=-0.240, P=0.023), while a positive correlation is found between carbohydrate of total diet calories and carbohydrate oxidation (r=0.263, P=0.013).Conclusion1. Metabolic disorder of calorie, protein, fat and carbohydrate exists in patients with newly diagnosed type 2 diabetes mellitus.2. Abdominal obesity exists in patients with newly diagnosed type 2 diabetes mellitus.3. Gender is one of influencing factors for REE of patients with newly diagnosed type 2 diabetes mellitus. And this influence results from the difference on body composition between male and female.4. Level of fasting plasma glucose is one of influencing factors for REE of patients with newly diagnosed type 2 diabetes mellitus.5. Fat free mass is one of influencing factors for REE of patients with newly diagnosed type 2 diabetes mellitus. C-reactive protein and recent total diet calories also influence REE.6. Level of fasting plasma glucose in patients with new diagnosed type 2 diabetes mellitus is associated with metabolic disorder of protein.7. Fat and carbohydrate of total diet calories have an effect on RQ.