Diabetes Care, Vol 20, Issue 6 988-991, Copyright © 1997 by American Diabetes Association
Age and sex effects on HbA1c. A study in a healthy Chinese population
YC Yang, FH Lu, JS Wu and CJ Chang
Department of Family Medicine, National Cheng Kung University Hospital, Tainan, Taiwan. yiching@mail.ncku.edu.tw
OBJECTIVE: To evaluate whether glycohemoglobin levels increase with age in
both sexes and to determine the effect of BMI on this increment. RESEARCH
DESIGN AND METHODS: A cross-sectional survey of 4,580 healthy Chinese men
and women, aged 20-85 years, was performed. All subjects who did not have
identifiable diseases and who were not on medication known to influence
glucose tolerance were recruited from participants at the preventive
services of the National Cheng-Kung University Hospital. As an indicator of
plasma glucose levels, glycohemoglobin was measured. The subjects were
classified according to their age and BMI for both men and women, and any
relationships with glycohemoglobin levels were evaluated. RESULTS: In all
the BMI groups divided into quartiles, glycohemoglobin levels increased
with age. The largest elevation of glycohemoglobin was observed in the 45-
to 54-year-old age-group, except in men with a BMI between the lowest and
highest quartiles. The group with a BMI above the highest quartile had a
higher glycohemoglobin than the group with a BMI below the lowest quartile
in men aged < 54 years and women aged 35-64 years. Men had higher
average glycohemoglobin levels than women < 55 years of age.
CONCLUSIONS: The age factor itself may cause an elevation in
glycohemoglobin independent of other age-related factors in Chinese men and
women, and there is a sex difference with a lower average glycohemoglobin
level in women before menopause. Furthermore, BMI, but not a family
predisposition to diabetes or leisure-time physical activity, affects this
age-dependent increase in glycohemoglobin levels.