According to the "Clinical Journal of the American Society of Nephrology," large numbers of studies since 2003 have linked smoking to decreased renal function. Smoking increases the risk of chronic kidney disease, or CKD, which may lead to end-stage renal disease, or ESRD. The Multiple Risk Factor Intervention Trial, or MRFIT, studied 332,544 men and found that smoking greatly increased the risk of ESRD.
Arteries Are Damaged
The Surgeon General reported in 2004 that smoking caused changes in artery linings, which secrete growth factors that attract inflammatory cells and cytokines. This causes inflammation and leads to atherosclerosis, which affects the blood supply to the kidneys. Smoking goes hand in hand with the development of cardiovascular disease and CKD. Chronic kidney disease increases the risk of cardiovascular disease, which damages the arteries and their linings. Smoking just two cigarettes more than doubles the amount of damaged endothelial cells circulating in the blood of healthy individuals, according to results of studies of healthy nonsmokers by Dr. James W. Davis and colleagues, published in "Clinical Pharmacology and Therapeutics."
Glomerular Filtration Rate Increases
Hemodynamics is the study of how the blood flow in the body affects the heart. Smoking increases heart rate and blood pressure, due to the effects of nicotine. Blood pressure immediately rises as soon as a person inhales. Certain drugs for high blood pressure, such as beta blockers, are less effective in smokers. Norvasc, used to relax blood vessels and lower blood pressure, becomes less effective on arterial stiffness.
The hemodynamics of the renal system is also affected. Pressure increases cause damage to the glomeruli, which are tiny filters in the kidney. As the glomerular filtration rate (GFR) increases, so does the amount of kidney damage. The GFR is a good indicator of how well the kidneys are functioning. Smoking also affects the renal artery, which is the main blood source to the kidneys.
Tobacco Chemicals and the Kidney
Cancer Research UK reports that cigarettes contain over 4000 chemicals, of which at least 80 are cancer-causing. Low-tar cigarettes still carry the same toxic chemicals found in any cigarette, and they are no safer to smoke. According to HealthCommunities.com, the ingredient of arsenic can build up over time and lead to acute tubular necrosis with acute renal failure. This is a condition in which the cells of the tubules, which carry urine to the ureters, begin to die due to lack of oxygen. This leads to acute renal failure, or sudden loss of kidney function.
A two-year study by P. C. Chan and colleagues for the National Toxicology Program found that male rats given inhaled ethyl benzene, another tobacco ingredient, had an increase in tumors of the renal tubules.
Smokers also have a higher risk of kidney cancer, according to the Siteman Cancer Center at the University of Washington School of Medicine. Inhaling the smoke allows chemicals to pass into their urine. All the many chemicals in tobacco then cause cancerous cells in the kidneys, leading to kidney cancer.
One of the first studies to show a strong connection between smoking and kidney function was the Cardiovascular Health Study Cohort in 2000, which involved 4142 nondiabetic participants. Much of the kidney damage may be halted or reversed by quitting smoking. Many aids are available to help people stop smoking, including medications, smoking cessation classes and patches. Since nicotine is highly addictive, the best choice is to never start smoking.