Effect of smoking on estimated glomerular filtration rate in a male occupational population

  Objective  To investigate the effect of smoking on estimated glomerular filtration rate (eGFR) in a male occupational population for providing evidence to tobacco control and prevention of chronic kidney disease (CKD).

  Methods  A face-to-face questionnaire survey, physical examination and laboratory testing were conducted from June 2018 to June 2019 among 1 760 male employees recruited with cluster random sampling in a large state-owned enterprise in Xuzhou city, Jiangsu province. The simplified diet in renal disease (MDRD) formula was used to calculate eGFR of the participants and logistic regression analysis was adopted to analyze the effect of smoking (pack years) on eGFR.

  Results  For all the participants, the self-reported smoking rate was 62.67% and the detection rate of abnormal eGFR was 13.24%. The average eGFR (ml/min/1.73 m²) was 123.42 ± 26.27 for non-smokers and 119.05 ± 23.54, 113.72 ± 24.06, and 102.31 ± 24.86 for light, moderate, and heavy smokers, respectively; the eGFR decreased significantly with the increase of smoking quantity (F = 43.07, P < 0.001). The detection rate of abnormal eGFR was 8.37% in non-smokers and the rate was 10.53%, 15.06%, and 31.82% in light, moderate, and heavy smokers and there was a significant dose-effect relationship between smoking quantity and detection rate of abnormal eGFR (χ² = 67.06, P < 0.001). After adjusting for age, waist circumference, hip circumference, alcohol drinking, systolic blood pressure, diastolic blood pressure, fasting plasma glucose, total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and creatinine and in comparison with the non-smokers, the risk of eGFR abnormality increased significantly in the moderate smokers (odds ratio OR = 1.67, 95% confidence interval 95% CI: 1.07 – 2.61) and in the heavy smokers (OR = 3.36, 95% CI: 2.14 – 5.28); when excluding the participants with newly diagnosed hypertension, the risk of abnormal eGFR was significantly higher for the moderate smokers (OR = 2.91, 95% CI: 1.50 – 5.64) and heavy smokers (OR = 4.38, 95% CI: 2.13 – 9.00) compared to the non-smokers; while, excluding the participants with newly diagnosed diabetes, the risk of abnormal eGFR was significantly higher for the moderate smokers (OR = 1.68, 95% CI: 1.04 – 2.72) and heavy smokers (OR = 3.78, 95% CI: 2.31 – 6.20) contrasting to the non-smokers.

  Conclusion  Smoking can significantly reduce eGFR in dose-effect manner among male occupational people.