High prevalence of undiagnosed diabetes and abnormal glucose tolerance in the Iranian urban population: Tehran Lipid and Glucose Study.
BACKGROUND
To estimate the prevalence of diagnosed and undiagnosed diabetes mellitus, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT in a large urban Iranian population aged > or = 20 years.


METHODS
The study population included 9,489 participants of the Tehran Lipid and Glucose Study with full relevant clinical data. Age-standardized prevalence of diabetes and glucose intolerance categories were reported according to the 2003 American Diabetes Association definitions. Age-adjusted logistic regression models were used to estimate the numbers needed to screen (NNTS) to find one person with undiagnosed diabetes.


RESULTS
The prevalence of diagnosed and undiagnosed diabetes, isolated IFG, isolated IGT, and combined IFG/IGT were 8.1%, 5.1%, 8.7%, 5.4% and 4.0% in men and 10%, 4.7%, 6.3%, 7.6%, and 4.5% in women respectively. Participants with undiagnosed diabetes had higher age, body mass index (BMI), waist circumference, systolic and diastolic blood pressures, triglycerides (all p values <0.001) and lower HDL-cholesterol (only in women, p < 0.01) compared to normoglycemic subjects. Undiagnosed diabetes was associated with family history of diabetes, increased BMI (> or = 25 kg/m2), abdominal obesity, hypertriglyceridemia, hypertension and low HDL-cholesterol levels. Among men, a combination of increased BMI, hypertension, and family history of diabetes led to a NNTS of 1.6 (95% CI: 1.57-1.71) and among women a combination of family history of diabetes and abdominal obesity, yielded a NNTS of 2.2 (95% CI: 2.1-2.4).


CONCLUSIONS
In conclusion, about one third of Tehranian adults had disturbed glucose tolerance or diabetes. One- third of total cases with diabetes were undiagnosed. Screening individuals with BMI > or = 25 kg/m2 (men), hypertension (men), abdominal obesity (women) and family history of diabetes may be more efficient.
Hadaegh
Farzad
F
Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University (M.C), Tehran, Iran. fzhadaegh@endocrine.ac.ir
Bozorgmanesh
Mohammad Reza
MR
Ghasemi
Asghar
A
Harati
Hadi
H
Saadat
Navid
N
Azizi
Fereidoun
F
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000886:Anthropometry; D001786:Blood Glucose / Q000032:analysis; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000453:epidemiology*; D015444:Exercise; D005260:Female; D018149:Glucose Intolerance / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000627:therapeutic use; D007492:Iran / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D012306:Risk; D012494:Sampling Studies; D017678:Sex Distribution; D014505:Urban Population / Q000706:statistics & numerical data
D001786:Blood Glucose; D007004:Hypoglycemic Agents