BACKGROUNDThere are studies suggesting smoking may increase the risk of type 2 diabetes. Effects of smoking on insulin secretion and insulin resistance (IR) are, however, controversial.

METHODSThis is a cross-sectional study. Since there were very few smokers among Hong Kong Chinese women, only men (n = 1068) were analyzed in this report. Fasting and 2-hour plasma glucose and insulin were measured. Insulinogenic index as well as beta-cell function and IR based on homeostatic model assessment (HOMA) by computer model (HOMA Calculator v2.2) were calculated.

RESULTSOf the 1068 men, 147 had newly diagnosed diabetes, 131 newly diagnosed impaired glucose tolerance (IGT) and 790 were non-diabetic normal controls. Smokers had similar fasting and 2-hour insulin levels, insulinogenic index and HOMA derived beta-cell function as compared to non-smokers in the groups with diabetes, IGT or normal oral glucose tolerance test (OGTT). IR was also similar between smokers, ex-smokers and non-smokers in those with normal OGTT. In men with IGT or diabetes, after adjustment for age and body mass index, smokers were more insulin resistant as compared to non-smokers (IR, IGT: 1.59 +/- 1.07 vs 1.03 +/- 0.54, P < 0.05; diabetes: 1.96 +/- 1.36 vs 1.06 +/- 0.45, P < 0.01). With Logistic regression analysis, comparing smokers and non-smokers, IR was independently associated with smoking (odds ratio (95% CI), IGT: 2.23 (1.05, 4.71); diabetes: 3.92 (1.22, 12.58)). None of the other insulin parameters enter into the model among those with normal OGTT or comparing ex-smokers and non-smoker or smokers and ex-smokers.

CONCLUSIONSIn Chinese men, smoking did not show any direct association with insulin levels and pancreatic insulin secretion. Smoking men with IGT or diabetes appeared more insulin resistant than their non-smoking counterparts.

Adult ; Female ; Glucose Intolerance ; metabolism ; Humans ; Insulin ; secretion ; Insulin Resistance ; Insulin-Secreting Cells ; secretion ; Male ; Middle Aged ; Smoking ; metabolism

PURPOSETo review evidence-based management of nephropathy in patients with type 2 diabetes.

DATA SOURCESA literature search (MEDLINE 1966 to 2000) was performed using the key word "diabetic nephropathy". Relevant book chapters were also reviewed.

STUDY SELECTIONWell-controlled, prospective landmark studies and expert review articles on diabetic nephropathy were selected.

DATA EXTRACTIONData and conclusions from the selected articles that provide solid evidence to the optimal management of diabetic nephropathy were extracted and interpreted in light of our clinical research experience with many thousands of Hong Kong Chinese patients.

RESULTSHypertension, long diabetes duration, poor glycaemic control and central obesity are the most important risk factors. Microalbuminuria is a practical marker to predict overt nephropathy in type 2 diabetic patients. Risk factor modification, renal function monitoring and combined therapies are the current integrated approaches to manage patients with diabetic kidney disease. Optimal glycaemic control is the mainstay of treatment but effective antihypertensive therapy is also key to delaying the progression of diabetic nephropathy. Angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists have important renoprotective actions independent of their blood pressure lowering actions.

CONCLUSIONSDiabetic nephropathy is the leading cause of end-stage renal disease worldwide. Monitoring renal function and screening for microalbuminuria will allow the identification of patients with nephropathy at a very early stage for intervention. Tight glycaemic control and aggressive antihypertensive treatment as well as the use of renin-angiotensin system inhibitors should substantially delay the progression of nephropathy.

Albuminuria ; diagnosis ; therapy ; Blood Glucose ; analysis ; Diabetes Mellitus, Type 2 ; complications ; Diabetic Nephropathies ; epidemiology ; therapy ; Dietary Proteins ; administration & dosage ; Humans ; Hyperlipidemias ; therapy ; Hypertension ; therapy