Cigarette smoking is associated with low glomerular filtration rate in male patients with type 2 diabetes.
OBJECTIVE
The relationship between cigarette smoking and renal dysfunction in diabetes has predominantly been documented in patients with type 1 diabetes. The aim of the present study was to explore the relationship between cigarette smoking and glomerular filtration rate (GFR) in a large cross-sectional study carried out in male subjects with type 2 diabetes. The role of metabolic syndrome in modulating this relationship was also investigated.


METHODS
One hundred fifty-eight current smokers and 158 never smokers with type 2 diabetes were consecutively recruited. Low GFR was defined as GFR <60 ml/min per 1.73 m(2).


RESULTS
The proportion of patients affected by low GFR was significantly higher in current smokers (20.9 vs. 12.0%, P = 0.03). The adjusted risk (odds ratio [OR]) of low GFR in current smokers was 2.20 (95% CI 1.14-4.26, P = 0.02) and markedly higher in patients from the first tertile of disease duration (4.27 [1.26-14.40], P = 0.02). When metabolic syndrome was added to the statistical model exploring the relationship between smoking and low GFR, the risk of low GFR showed a small change, although it did not become any more significant (1.84 [0.98-3.45], P = 0.06). Current smokers showed even higher free oxygen radical test unit values (560.0 +/- 91.5 vs. 442.7 +/- 87.2, P < 0.0001).


CONCLUSIONS
In a large population of male patients with type 2 diabetes, the risk of low GFR is markedly enhanced by smoking and is at least partially mediated by metabolic syndrome.
De Cosmo
Salvatore
S
Unit of Endocrinology and Metabolic Diseases, Department of Medical Sciences, University of Foggia, via Luigi Pinto, 71100 Foggia, Italy.
Lamacchia
Olga
O
Rauseo
Anna
A
Viti
Raffaella
R
Gesualdo
Loreto
L
Pilotti
Alessandra
A
Trischitta
Vincenzo
V
Cignarelli
Mauro
M
D000368:Aged; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000378:metabolism / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000453:epidemiology* / Q000378:metabolism / Q000503:physiopathology; D005919:Glomerular Filtration Rate; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D017382:Reactive Oxygen Species / Q000378:metabolism; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*
D017382:Reactive Oxygen Species