D-chiro-inositol is thought to regulate insulin action and improve insulin resistance in diabetic rodent models and type 2 diabetic patients. However, there is no study on the effects of DCI on insulin resistance and quality of life in patients with severe forms of type 2 diabetes mellitus. The aim of this study is to investigate the effects of D-chiro-inositol(DCI) on insulin resistance, quality of life, and SDSCA(Summary of Diabetes Self-Care Activities) in patients with type 2 diabetes mellitus(HbA1c>7.0%).
A randomized, double-blind, placebo-controlled study was performed on 46 patients with type 2 diabetes mellitus who visited the Chungnam National University Hospital from March 2015 to May 2016. We analyzed the changes in diverse biochemical laboratory parameterss including HbA1c, fasting glucose, fasting insulin, and fasting c-peptide, as well as diverse metabolic parameters, including body mass index, body weight, and BP to evaluate DCI effects in patients with type 2 diabetes mellitus. In addition, the effects of DCI treatment on the quality of life, and SDSCA were assessed. To evaluate the effects of DCI, a paired t-test and ANCOVA were used. Path analysis was used to investigate the relationship of diverse parameters with the quality of life.
DCI treatment in participants resulted in significantly reduced HbA1c levels 8.75±0.79%(baseline), 8.36±1.03%(after 12weeks), and 8.65±0.81%(after 24weeks). However, there was no significant change in the participants treated with placebo. Comparison of diverse clinical parameters, and biochemical laboratory findings revealed that there was no significant difference between the DCI and Control groups.
Interestingly, both DCI and control groups significantly showed improvements in SDSCA. There were no significant differences in the quantitative levels of quality of life in the placebo group, but the DCI group revealed significant improvements in the quantitative levels of quality of life, from 73.05±16.85 to 82.74±10.68. In the analysis of sub-parameters of quality of life, there were significant increases in physical functioning, role limit-physical, role limit-emotional, bodily pain, general health and vitality.
In the correlation analysis, there were significant negative correlation between the changes in body mass index and fasting c-peptide(r=-0.418, p<0.05), and between changes in fasting glucose and diabetes self management(r=-0.505, p< 0.05) in the DCI treatment group. Moreover, there was a significant positive correlation in the changes of fasting insulin with changes of fasting c-peptide (r=0.545, p<0.01) in DCI treatment group.
Using pathway analysis, the most influential factors to the fasting glucose were changes SDSCA(β=-0.505, t=-2.743). The most influential factors to the quality of life were changes of SDSCA(β=0.411, t=2.024) and fasting c-peptide(β=-0.445, t=-2.668) in DCI treatment group.
In conclusion, treatment of DCI effectively improved glucose control in patients with type 2 DM(HbA1c level>7.0%) after 12 weeks of treatment, although the improvements of glucose control was not observed after 24 weeks of treatment. Improvement of glucose control may encourage more frequent SDSCA in patients, and improve the quality of life. Based on the present study, we suggest that diabetes self management, as well as consideration of comprehensive laboratory findings, may be important factors in regulating the quality of life in type 2 DM patients.