Peripheral total and differential leukocyte count in diabetic nephropathy: the relationship of plasma leptin to leukocytosis.
OBJECTIVE
Because of increasing evidence that white blood cells (WBCs) play a role in the development and progression of diabetes complications, this study aimed to investigate the relation of circulating total and differential leukocyte counts to nephropathy in patients with type 2 diabetes. Plasma leptin levels were also measured to investigate their role in peripheral leukocytosis.


METHODS
For this study, 1,480 subjects with type 2 diabetes who were enrolled in a disease management program were stratified according to urinary microalbumin and serum creatinine measurements. The total and differential leukocyte profiles of peripheral blood were measured and plasma leptin was examined by enzyme-linked immunosorbent assay. Demographic and potential metabolic confounding factors were analyzed with linear and logistic regression to calculate the effects of leukocyte count on diabetic nephropathy.


RESULTS
The peripheral total WBC, monocyte, and neutrophil counts increased in parallel with the advancement of diabetic nephropathy. In contrast, the lymphocyte count decreased. When WBC counts were analyzed per quartile and as continuous variables after adjusting for age, sex, and other known risk factors with multiple regression analysis, peripheral total WBC, monocyte, neutrophil, and lymphocyte counts were independently and significantly associated with diabetic nephropathy. Plasma leptin levels increased in patients with nephropathy and correlated significantly with total WBC count (r = 0.194, P = 0.014).


CONCLUSIONS
Because leukocytes are activated and secrete cytokines in the diabetic state and leptin stimulates leukocyte proliferation and differentiation, our results suggest that circulating leukocytes contribute to the development and progression of nephropathy, partially through the effects of leptin, in patients with type 2 diabetes.
Chung
Fu-Mei
FM
Department of Clinical Research, Pingtung Christian Hospital, No. 60, Da-Lien Rd., Pingtung 90000, Taiwan.
Tsai
Jack C-R
JC
Chang
Dao-Ming
DM
Shin
Shyi-Jang
SJ
Lee
Yau-Jiunn
YJ
D000419:Albuminuria; D015415:Biomarkers; D003404:Creatinine / Q000097:blood; D003928:Diabetic Nephropathies / Q000097:blood* / Q000652:urine; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D007958:Leukocyte Count; D007964:Leukocytosis / Q000453:epidemiology*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors
D015415:Biomarkers; D020738:Leptin; D003404:Creatinine