The role of the body mass index and triglyceride levels in identifying insulin-sensitive and insulin-resistant variants in Japanese non-insulin-dependent diabetic patients.
Using the minimal model approach shown by Bergman, our group had previously shown 2 variants among non-obese mildly diabetic patients, one with normal insulin sensitivity and the other with insulin resistance. The present study examines whether these 2 variants exist in the ordinary Japanese non-insulin-dependent diabetes mellitus (NIDDM) population and compares the clinical profile between the 2 discrete forms of NIDDM. In addition, we investigated the factors responsible for insulin resistance observed in Japanese NIDDM populations. One hundred eleven untreated Japanese NIDDM subjects (fasting glucose < 10 mmol/L) were assessed for insulin action (homeostasis model assessment [HOMA-IR] = fasting serum insulin (microU/mL) x fasting plasma glucose (mmol/L)/22.5) and the fasting lipid profile. Sixty percent of these patients had normal insulin sensitivity (HOMA-IR < 2.5). The insulin-resistant patients had higher serum cholesterol (188.1 +/- 5.2 v 182.2 +/- 3.9 mg/dL, P> .05) and low-density lipoprotein (LDL) cholesterol (501.2 +/- 16.7 v 469.4 +/- 14.8 mg/dL, P > .05) than the insulin-sensitive patients, but the difference was not statistically significant. In contrast, the former group had a significantly higher body mass index ([BMI] 26.6 +/- 0.8 v 21.7 +/- 0.4 kg/m2, P < .0001) and higher serum triglycerides (181.0 +/- 16.4 (range, 79 to 545) v 95.1 +/- 4.1 (range, 36 to 204) mg/dL, P < .0001) and lower high-density lipoprotein (HDL) cholesterol (47.2 +/- 1.7 v 58.2 +/- 2.5 mg/dL, P < .005) than the latter group. HOMA-IR was related to the BMI. Fifteen of 17 (88%) NIDDM patients with a BMI greater than 27.0 were insulin-resistant, whereas 35 of 38 (92%) NIDDM patients with a BMI less than 21.5 were insulin-sensitive. In the midrange BMI (21.5 to 27.0 kg/m2), patients were equally likely to be insulin-resistant or insulin-sensitive. Analysis of the midrange BMI group showed that HOMA-IR was associated with serum triglycerides (P < .0001) but not with the BMI. These data suggest the following conclusions: (1) Japanese NIDDM patients can be classified into 2 populations, one with normal insulin sensitivity and the other with insulin resistance; (2) NIDDM patients with normal insulin action have a low cardiovascular disease risk factor, whereas those with insulin resistance have a markedly increased cardiovascular disease risk factor; and (3) the BMI and serum triglyceride level per se are associated with insulin action in Japanese NIDDM populations.
Taniguchi
A
A
First Department of Internal Medicine, Kansai-Denryoku Hospital, Osaka, Japan.
Fukushima
M
M
Sakai
M
M
Kataoka
K
K
Nagata
I
I
Doi
K
K
Arakawa
H
H
Nagasaka
S
S
Tokuyama
K
K
Nakai
Y
Y
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000145:classification / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood*
D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol