Association between serum bioavailable testosterone concentration and the ratio of glycated albumin to glycated hemoglobin in men with type 2 diabetes.
OBJECTIVE
Testosterone stimulates erythropoiesis and thus glycated hemoglobin (A1C) values may be relatively low in male diabetic patients with hypogonadism. We therefore investigated relationships between serum bioavailable testosterone concentration and the ratio of glycated albumin (GA) to A1C and between serum bioavailable testosterone and hemoglobin concentrations in men with type 2 diabetes.


METHODS
The above relationships were investigated in 222 consecutive men with type 2 diabetes. We also investigated how the ratio of GA to A1C is related to other variables such as age, BMI, and degree of diabetic microangiopathy.


RESULTS
Mean ratio of GA to A1C was 2.94 +/- 0.38. Serum bioavailable testosterone concentration correlated positively with hemoglobin concentration (r = 0.368, P < 0.0001) and negatively with the ratio of GA to A1C (r = -0.278, P < 0.0001). Multiple regression analyses identified serum bioavailable testosterone concentration (beta = 0.187, P = 0.0062), age (beta = -0.204, P = 0.0075), BMI (beta = 0.151, P = 0.0302), systolic blood pressure (beta = 0.173, P = 0.0090), and plasma total cholesterol (beta = 0.155, P = 0.0141) as independent determinants of hemoglobin concentration; moreover, serum bioavailable testosterone concentration (beta = -0.155, P = 0.0381) and plasma total cholesterol (beta = -0.170, P = 0.0144) were identified as independent determinants of the ratio of GA to A1C.


CONCLUSIONS
Serum bioavailable testosterone concentration correlated positively with hemoglobin concentration and negatively with the ratio of GA to A1C in men with type 2 diabetes, which may lead to underestimation of A1C in hypogonadal men with type 2 diabetes.
Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. sayarinapm@hotmail.com
Michiaki
M
Fukui
Muhei
M
Tanaka
Goji
G
Hasegawa
Toshikazu
T
Yoshikawa
Naoto
N
Nakamura
D000368:Aged; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D017127:Glycation End Products, Advanced; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012709:Serum Albumin / Q000378:metabolism*; D013739:Testosterone / Q000097:blood*; D000093423:Glycated Serum Albumin
D002784:Cholesterol; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D013739:Testosterone; D000093423:Glycated Serum Albumin