It is generally assumed that there is a negative linear association between androgen receptor (AR) sensitivity and the CAG repeat length. However, correlation between CAG repeat length and clinical factors of metabolic syndrome (MS), late onset hypogonadism is unclear. In this study we explored the relationship between AR CAG repeat length polymorphism and MS, late onset hypogonadism (LOH) in a Korean male population.
The association between AR CAG repeat length polymorphism and MS was analyzed in 241 Korean men (20–90 years old). MS was diagnosed according to the NCEP criteria (any three or more of the following components were present: abdominal obesity [waist circumference (WC) >102 cm], triglycerides >150 mg/dL, HDL cholesterol <40 mg/dL, fasting glucose >110 mg/dL, or blood pressure of >130/85 mmHg). LOH was diagnosed by serum testosterone level of <3.5 ng/mL and androgen deficiency in the aging male questionnaire positive. AR CAG repeat length polymorphism was determined by microsatellite fragment sizing and association with clinical factors and questionnaire related with LOH [patient health questionnaire-9 (PHQ), aging male symptom scale (AMS), and international index of erectile function (IIEF)] were analyzed.
Mean age of the patients was 56.9±11.2 years. Mean AR CAG repeat length and serum testosterone levels were 26.7±8.9 and 5.6±2.3 ng/mL, respectively. A Total of 64 men (26.6%) were diagnosed with MS and 22 men were diagnosed with LOH. Men with MS showed no significant difference in AR CAG repeat length compared with men without MS (P=0.325). AR CAG repeat length was not associated with HDL, LDL, triglyceride (P=0.397, P=0.609, P=0.867), but showed significant association with HbA1c (r=0.103, P=0.029). Men with LOH showed no significant difference in AR CAG repeat length compared with men without LOH (P=0.665). However as CAG repeat length was increased, AMS and PHQ scores were decreased and IIEF score was increased, significantly (r=−0.118, r=−0.153, r=0.069) (P<0.01, P<0.01, P<0.01).