title: The associations of body mass index, C-peptide and metabolic status in Chinese Type 2 diabetic patients.
abstract: BACKGROUND
  Chinese Type 2 diabetic subjects are generally less obese than their Caucasian counterparts. We hypothesized that lean and obese Chinese Type 2 diabetic subjects have different metabolic and insulin secretory profiles. We compared the clinical features, C peptide and metabolic status between lean/normal weight and obese diabetic subjects.
  
  
  METHODS
  We conducted a cross-sectional study on 521 consecutive diabetic subjects newly referred to a Diabetes Clinic in 1996. The subjects were categorized into underweight (< 18.5 kg/m(2)), normal weight (18.5-23 kg/m(2)) and overweight (>/= 23 kg/m(2)) according to the re-defined WHO criterion for obesity in Asia Pacific Region. Metabolic and anthropometric parameters were compared between groups with different levels of obesity.
  
  
  RESULTS
  In this cohort, 5.8, 30.6 and 63.7% of subjects were underweight, normal weight and overweight, respectively, using the 'Asian' criteria. Of these 521 subjects, 20% had fasting C-peptide less than 0.2 nmol/l, suggesting insulin deficiency. Fasting C-peptide showed linear increasing trend (P < 0.001) while HbA(1c) showed decreasing trend (P = 0.001) with BMI after adjustment for duration of disease. There were more subjects in the underweight group who were treated with insulin (41.3% vs. 13.9 and 8.2%, P < 0.001). Although homeostasis model assessment was similar amongst the three groups, systolic (P = 0.006) and diastolic blood pressure (P < 0.001) and triglyceride (P < 0.001) showed increasing, while HDL-C (P < 0.001) showed decreasing, trends across different BMI groups. The underweight patients had the lowest C-peptide and highest HbA(1c) while overweight patients had the highest C-peptide, blood pressure, triglyceride but lowest HbA(1c) levels.
  
  
  CONCLUSIONS
  In Chinese Type 2 diabetic patients, lean subjects had predominant insulin deficiency and obese subjects had features of metabolic syndrome. Clinicians should have low threshold to initiate insulin therapy in lean Type 2 diabetic patients with suboptimal glycaemic control. In obese diabetic patients, aggressive control of multiple cardiovascular risks is of particular importance.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong and The Diabetes Mellitus and Endocrine Centre, The Prince of Wales Hospital, Shatin, Hong Kong. wbchan@cuhk.edu.hk
authors.forename: W B
authors.initials: WB
authors.lastname: Chan
authors.forename: P C Y
authors.initials: PC
authors.lastname: Tong
authors.forename: C C
authors.initials: CC
authors.lastname: Chow
authors.forename: W Y
authors.initials: WY
authors.lastname: So
authors.forename: M C Y
authors.initials: MC
authors.lastname: Ng
authors.forename: R C W
authors.initials: RC
authors.lastname: Ma
authors.forename: R
authors.initials: R
authors.lastname: Osaki
authors.forename: C S
authors.initials: CS
authors.lastname: Cockram
authors.forename: J C N
authors.initials: JC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood* / Q000628:therapy; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000628:therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006723:Hong Kong / Q000208:ethnology; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity; D010353:Patient Education as Topic
chemical_list: D002096:C-Peptide; D002784:Cholesterol; D006442:Glycated Hemoglobin; D007328:Insulin