Low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio is the best surrogate marker for insulin resistance in non-obese Japanese adults.
BACKGROUND
The aim of the present study was to examine how lipid profiles are associated with insulin resistance in Japanese community-dwelling adults.


METHODS
This cross-sectional study included 614 men aged 58 ± 14 (mean ± standard deviation; range, 20-89) years and 779 women aged 60 ± 12 (range, 21-88) years. The study sample were 1,042 (74.8%) non-obese (BMI < 25.0 kg/m²) and 351 (25.2%) overweight (BMI ≥ 25 kg/m²) subjects. Insulin resistance was defined by homeostasis model assessment of insulin resistance (HOMA-IR) of at least 2.5. The areas under the curve (AUC) of the receiver operating characteristic curves (ROC) were used to compare the power of these serum markers.


RESULTS
In non-obese subjects, the best marker of insulin resistance was low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio of 0.74 (95% confidence interval (CI), 0.66-0.80). The HDL-C, triglyceride (TG)/HDL-C ratio, and non-HDL-C also discriminated insulin resistance, as the values for AUC were 0.31 (95% CI, 0.24-0.38), 0.69 (95% CI, 0.62-0.75) and 0.69 (95% CI, 0.62-0.75), respectively. In overweight subjects, the AUC for TG and TG/HDL-C ratio were 0.64 (0.58-0.71) and 0.64 (0.57-0.70), respectively. The optimal cut-off point to identifying insulin resistance for these markers yielded the following values: TG/HDL-C ratio of ≥ 1.50 and LDL-C/HDL-C ratio of ≥ 2.14 in non-obese subjects, and ≥ 2.20, ≥ 2.25 in overweight subjects. In non-obese subjects, the positive likelihood ratio was greatest for LDL-C/HDL-C ratio.


CONCLUSIONS
In non-obese Japanese adults, LDL-C/HDL-C ratio may be the best reliable marker of insulin resistance.
Department of Community Medicine, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. rykawamo@yahoo.co.jp
Ryuichi
R
Kawamoto
Yasuharu
Y
Tabara
Katsuhiko
K
Kohara
Tetsuro
T
Miki
Tomo
T
Kusunoki
Shuzo
S
Takayama
Masanori
M
Abe
Tateaki
T
Katoh
Nobuyuki
N
Ohtsuka
D000328:Adult; D019540:Area Under Curve; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000097:blood; D050177:Overweight / Q000097:blood; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014280:Triglycerides