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

• Published in: Metabolism, clinical and experimental clinical and experimental, 2000-08, Vol.49 (8), p.1001-1005
• Main Authors: Taniguchi, Ataru, Fukushima, Mitsuo, Sakai, Masahiko, Kataoka, Kiyoshi, Nagata, Itaru, Doi, Kentaro, Arakawa, Hiroaki, Nagasaka, Shoichiro, Tokuyama, Kumpei, Nakai, Yoshikatsu
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Blood Glucose - metabolism; Body Mass Index; Cholesterol - blood; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - classification; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Fasting; Female; Humans; Insulin - blood; Insulin Resistance - physiology; Male; Medical sciences; Middle Aged; Triglycerides - blood
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1053/meta.2000.7735

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 (μU/mL) × 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/m 2, 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/m 2), 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.