The Influence of Smoking on Renal Functions Among Apparently Healthy Smokers

Abstract

Background Cigarette smoking is an important modifiable risk factor in kidney disease progression. Although long-term smoking has been associated with chronic kidney disease (CKD), its effect on kidney function in early stages has not been clarified. Objective To detect the early effects of smoking either active or passive on kidney functions. Methodology The current study was comparative cross sectional study conducted on 280 participants, 140 were non‑smokers and 140 were smokers (70 passive smokers and 70 active smokers). The two groups were comparable in terms of all parameters. We investigated the possible effects of smoking on kidney functions using both serum kidney function tests especially; serum urea, serum creatinine, serum cotinine levels and detection of albumin in urine. Smoking history, full Laboratory investigations, Ventilatory function test including (FEV1/FVC, FEV1, FEF 25–75%, VC and FVC) were done. Results Serum urea, serum creatinine, serum cotinine levels and urinary albumin were statistically significant higher in smokers group in comparison to nonsmokers, also the serum cotinine levels and urinary albumin were statistically significant in active smokers in comparison to passive smokers. There were positive correlations between the level of urinary albumin and pack/year (r = 0.9, p<0.05), smoking index (r = 0.9, p<0.05), smoking duration (r = 0.4, p<0.05), and serum cotinine (r = 0.6, p<0.050) with good statistical significance. The most significant predictive risk factors of microalbuminuria among smokers group in descending orders were active smoking, passive smoking, age and serum cotinine level. Conclusion Both active and passive smoking, especially among heavy smokers, is a significant risk factor for microalbuminuria. This finding increase the importance of early cessation of smoking in order to minimize early renal affection among healthy smokers that may not be discovered by routine renal function tests.

Correlation between Red Cell Distribution Width (RDW) and Mean Corpuscular Volume (MCV) as a Prognostic Biomarker for Diabetic Nephropathy Patients in a South Indian Hospital

“…Our study significantly difference in elevation in RDW, Urea, creatinine, RBS, FBS, PPBS, and HbA1C levels among patients with both smoking and alcohol consumption habits. A similar study conducted by Eid HA et al in 2022 concluded that increase in urea and creatinine levels, accompanied by a decline in eGFR values among patients with smoking and alcohol consumption habits [14]. Smoking can potentially inflict damage on the kidneys through diverse mechanisms, encompassing immediate effects such as sympathetic stimulation leading to reduced GFR, as well as on-going consequences, notably compromised endothelial cell functionality [15].…”

Active smoking in urban households: An association between urinary cotinine metabolite level and serum eGFR concentration

“…Additionally, a previous study showed that among smokers, higher serum concentrations of cotinine were significantly associated with serum creatinine compared with non-smokers 17 . Our results are similar to those of a previous study, which showed higher levels of creatinine-based eGFR and lower levels of cystatin C-based eGFR with higher quantities of smoking 11 .…”

“…The definition of an active cigarette smoker in this study was calculated using the smoking index (SI) as the number of packs smoked daily multiplied by the number of years of smoking. The SI was used to categorize active smokers as: 1) mild active cigarette smokers (SI<400 cigarettes/year), 2) moderate active cigarette smokers (SI = 400-800 cigarettes/year), and 3) heavy active cigarette smokers (SI ≥800 cigarettes/ year) 17,23 . The National Center for Health Statistics 2017 defined a current smoker as a person who has smoked ≥100 cigarettes in their lifetime and who is still smoking cigarettes 17 .…”

“…Nicotine is mainly transformed to cotinine (active metabolite), the primary proximate metabolite of nicotine, which is used most frequently as a biomarker of tobacco smoke exposure, as its half-life is longer (approximately 16-18 h), and its levels remain relatively constant during the day [13][14][15][16] . Cotinine is a good quantitative test for the detection of smoking exposure that can be measured in different body fluids, including saliva, plasma, and urine 17 .…”

Serum hydroxycotinine was associated with chronic kidney disease (CKD): a cross-sectional study based on NHANES

“…Eid HA et al. [ 15 ] found that serum cotinine was significantly positive with tobacco exposure, the research had reinforced a conclusion that there was a negative correlation between serum cotinine and the eGFR. However, the association between serum hydroxycotinine, transformed by continine, and CKD is yet to be elucidated.…”