Relationships between white blood cell count and insulin resistance, glucose effectiveness, and first- and second-phase insulin secretion in young adults

The Increasing prevalence of type 2 diabetes mellitus (T2DM) has been observed in younger adults. Insulin resistance [IR], decreased first-, second-phase insulin secretion, and glucose effectiveness (GE) (IR, first phase insulin secretion [FPIS], second phase insulin secretion [SPIS], and GE), denoted as diabetes factors (DF), are core for developing T2DM. A body of evidence has shown that inflammation contributes to the development of diabetes. In the present study, our goals were first, evaluate the relationships between white blood cell (WBC) count and, second, examine the relative tightness between the 4 DFs to WBC count. Thus, the pathophysiology of T2DM in Chinese young men could be more understood. 21112 non-obese males between 18 to 27 years old were recruited (mean age: 24.3 ± 0.017), including 1745 subjects with metabolic syndrome. DFs were calculated by the published equations by our groups as follows: IR = log (1.439 + 0.018 × sex - 0.003 × age + 0.029 × body mass index [BMI]- 0.001 × systolic blood pressure [SBP] + 0.006 × diastolic blood pressure + 0.049 × triglycerides [TG] - 0.046 × high-density lipoprotein cholesterol [HDLC] - 0.0116 × fasting plasma glucose [FPG]) × 10 (3.333)(1.) FPIS = 10 [1.477 - 0.119 × FPG + 0.079 × BMI - 0.523 × HDLC] (2.) SPIS = 10 [-2.4 - 0.088 × FPG + 0.072 × BMI]. GE = (29.196 - 0.103 × age - 2.722 × TG - 0.592 × FPG) ×10 (−3)(3.) The association between DFs and WBC count was analyzed using a simple correlation. The r-values of the simple correlation are regarded as the tightness of the relationships. Higher WBC, FPIS, SPIS, IR, age, BMI, blood pressure, FPG, TG, Cholesterol, low-density lipoprotein cholesterol and lower HDL-C and GE were observed in subjects with metabolic syndrome. A similar trend was seen across the quartiles of WBC levels. Among the 4 DFs, GE has the highest r-value (r = -0.093, P < .001), followed by IR (r = 0.067, P < .001), SPIS (r = 0.029, P < .001) and FPIS (r = 0.027, P < .001). Elevated WBC count is significantly associated with all the 4 DFs and the relative order of the tightness, from the highest to the lowest, are GE, IR, SPIS, and FPIS in Chinese young men.