Testosterone and modifiable risk factors associated with diabetes in men.
OBJECTIVE
The role of endogenous testosterone in the pathogenesis of type 2 diabetes mellitus remains vague. We investigated whether associations between endogenous testosterone and diabetes prevalence in men could be partially explained by modifiable risk factors.


METHODS
A random population-based cross-sectional study of 1195 men aged 35-80 years living in the north-west regions of Adelaide, Australia. Data collections occurred between 2002 and 2005, and response rate was 45.1%.


METHODS
Diabetes (non-specific) was classified by either: (1) self-report for doctor diagnosis of diabetes; (2) prescription medication for diabetes; (3) fasting plasma glucose ≥ 7 mmol/L; or (4) glycosylated haemoglobin ≥ 6.2%. Logistic regressions were used to estimate odds ratios (OR [with 95% confidence intervals]) for diabetes, with stepwise adjustments for demographic, lifestyle, and clinical factors.


RESULTS
Diabetes prevalence was positively associated with age groups 45-54 years (2.8 [1.4, 5.8]), 55-64 years (3.9 [1.9, 8.3]) and ≥ 65 years (4.0 [1.8, 8.9]), lowest income group (1.8 [1.0, 3.4]), ex-smoker (1.8 [1.2, 2.9]), lowest (3.2 [1.9, 5.5]) and middle (1.9 [1.1, 3.4]) alcohol tertiles, cardiovascular disease (1.9 [1.2, 2.8]), metabolic syndrome (4.0 [2.6, 6.1]), and lowest plasma total testosterone tertile (1.8 [1.1, 3.0]), but negatively associated with middle (0.5 [0.3, 0.8]) and highest (0.4 [0.3, 0.7]) sugar intake tertiles, arthritis (0.6 [0.3, 1.0]), and elevated LDL cholesterol (0.5 [0.3, 0.8]); ORs showed an inverted 'U' shape for middle and highest voiding lower urinary tract symptoms tertiles. Body composition, muscle strength, and cardio-metabolic factors partially explained the association between low plasma total testosterone and diabetes.


CONCLUSIONS
Plasma total testosterone was inversely and independently associated with diabetes prevalence, that might have been partially explained by several modifiable risk factors.
Royal Adelaide Hospital/Institute of Medical and Veterinary Science, South Australia Health, Government of South Australia, Adelaide, Australia. evan.atlantis@adelaide.edu.au
Evan
E
Atlantis
Kylie
K
Lange
Sean
S
Martin
Matthew T
MT
Haren
Anne
A
Taylor
Peter D
PD
O'Loughlin
Villis
V
Marshall
Gary A
GA
Wittert
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking; D001168:Arthritis / Q000150:complications; D001315:Australia / Q000453:epidemiology; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000150:complications; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D019422:Dietary Sucrose / Q000008:administration & dosage; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000150:complications; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D057566:Self Report; D012907:Smoking; D013739:Testosterone / Q000097:blood*; D014570:Urologic Diseases / Q000150:complications
D001786:Blood Glucose; D019422:Dietary Sucrose; D013739:Testosterone