The Rates of Age-Related Change of HbA1c, Fasting and 2-Hour Post-Challenged Plasma Glucose Concentrations Differ Significantly Between Normal and Abnormal Glucose Tolerant Subjects

Presentation Number: SUN 588
Date of Presentation: April 2nd, 2017

Maximiliano Hyon*1, Rudruidee Karnchanasorn2, Wei Feng1, Horng-Yih Ou3, Raynald Samoa1, Lee-Ming Chuang4 and Ken C Chiu1
1City of Hope National Medical Center, Duarte, CA, 2The University of Kansas Medical Center, Kansas City, KS, 3National Cheng-Kung University Medical College and Hospital, Tainan, Taiwan, 4National Taiwan Univesity Hospital, Taipei, Taiwan

Abstract

It has been demonstrated that diabetes mellitus is a progressive disease. Beta cell function declines with age in both glucose tolerant subjects as well as in subjects with type 2 diabetes. Furthermore, it has been shown that age-related beta cell function decrease is associated with rising fasting glucose concentration and HbA1c in glucose tolerant subjects. In normal glucose tolerant subjects (NGT), HbA1, fasting and 2-hour post-challenged plasma glucose concentrations (FPG, 2hPG) increase with aging. However, the rates of changes in subjects with abnormal glucose tolerance (AGT) have not reported as yet. This study is aimed to examine the rates of change of HbA1c, FPG, and 2hPG in AGT subjects and compare them with NGT subjects.

This study included 4,561 AGT subjects and 3,624 NGT subjects. Only adult subjects (aged 20 years or older) with BMI measured were included in this study. Diabetes subjects were excluded from the study as the treatment would affect HbA1c, FPG, and 2hPG. The states of glucose tolerance were determined by HbA1c, FPG, and 2hPG. The regression analyses were used to examine the relationship of age with HbA1c, FPG, and 2hPG. Multivariate correlations were explored with the following covariates: gender, BMI, race/ethnicity, family history of diabetes, smoking status, alcohol consumption, education, and poverty index. The age-related change rates were compared between AGT and NGT groups.

A significant correlation was observed in age with HbA1c (P<0.000001, r=0.2762), FPG (P<0.000001, r=0.0816), and 2hPG (P<0.000001, r=0.2625) in the AGT group. The correlations of age with HbA1c (P<0.000001, r=0.2690) and FPG (P<0.000001, r=0.1268) were confirmed in the NGT group and was also observed with 2hPG (P<0.0000001, r=0.2033) in the NGT group. Multivariate analyses confirmed the independent effect of age on HbA1c, FPG, and 2hPG in both AGT and NGT groups (all P<0.0000001 for age). In the fully adjusted model, the rates of change between the AGT and NGT groups differed significant higher in the AGT groups than the NGT group for HbA1c (P=0.00001, 0.0069±0.0003 vs. 0.0050±0.0003 %/year, respectively), FPG (P=0.048, 0.0619±0.0073 vs. 0.0433±0.0060, respectively), and 2hPG (P<0.000001, 0.5521±0.0291 vs. 0.2764±0.0223 mg/dL/year, respectively).

Our results demonstrate that age is an independent determinant for HbA1c, FPG, and 2hPG in both NGT and AGT groups. The rates of change in the AGT subjects are significantly higher by 1.27 times for HbA1c, by 1.43 times for FPG, and by 1.89 times for 2hPG than in the NGT subjects. From aging, the transition from AGT to overt diabetes will take 116 years for HbA1c, 420 years for FPG, and 109 years for 2hPG. Thus, aging is not primary determinant for the development of diabetes.

 

Nothing to Disclose: MH, RK, WF, HYO, RS, LMC, KCC