Smoking and Adverse Outcomes in Patients With CKD: The Study of Heart and Renal Protection (SHARP).
BACKGROUND
The absolute and relative importance of smoking to vascular and nonvascular outcomes in people with chronic kidney disease (CKD), as well its relevance to kidney disease progression, is uncertain.


METHODS
Observational study.


METHODS
9,270 participants with CKD enrolled in SHARP.


METHODS
Baseline smoking status (current, former, and never).


RESULTS
Vascular events, site-specific cancer, ESRD, rate of change in estimated glomerular filtration rate (eGFR), and cause-specific mortality.


RESULTS
At baseline, 1,243 (13%) participants were current smokers (median consumption, 10 cigarettes/day); 3,272 (35%), former smokers; and 4,755 (51%), never smokers. Median follow-up was 4.9 years. Vascular event rates were 36% higher for current than never smokers (2,317 events; relative risk [RR], 1.36; 95% CI, 1.19-1.55), reflecting increases in both atherosclerotic (RR, 1.49; 95% CI, 1.26-1.76) and nonatherosclerotic (RR, 1.25; 95% CI, 1.05-1.50) events. Cancer was 37% higher among current smokers (632 events; RR, 1.37; 95% CI, 1.07-1.76), with the biggest RRs for lung (RR, 9.31; 95% CI, 4.37-19.83) and upper aerodigestive tract (RR, 4.87; 95% CI, 2.10-11.32) cancers. For 6,245 patients not receiving dialysis at baseline, ESRD incidence did not differ significantly between current and never smokers (2,141 events; RR, 1.02; 95% CI, 0.89-1.17), nor did estimated rate of change in eGFR (current smokers, -1.77±0.14 [SE]; never smokers, -1.70±0.07mL/min/1.73m(2) per year). All-cause mortality was 48% higher among current smokers (2,257 events; RR, 1.48; 95% CI, 1.30-1.70), with significant increases in vascular (RR, 1.35; 95% CI, 1.07-1.69) and nonvascular (RR, 1.60; 95% CI, 1.34-1.91) causes of death, especially cancer (RR, 2.32; 95% CI, 1.58-3.40) and respiratory (RR, 2.25; 95% CI, 1.51-3.35) mortality.


CONCLUSIONS
Smoking status not assessed during follow-up.


CONCLUSIONS
In this study of patients with CKD, smoking significantly increased the risks for vascular and nonvascular morbidity and mortality, but was not associated with kidney disease progression. The associations with vascular and neoplastic disease are in keeping with those observed in the general population and are likely modifiable by cessation.
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
Natalie
N
Staplin
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
Richard
R
Haynes
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
William G
WG
Herrington
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
Christina
C
Reith
Menzies Institute, Darwin, Australia.
Alan
A
Cass
University Hospital, Uppsala, Sweden.
Bengt
B
Fellström
China Oxford Centre for International Health Research, Fuwai Hospital, Beijing, China.
Lixin
L
Jiang
University of Minnesota, Minneapolis, MN.
Bertram L
BL
Kasiske
Division of Nephrology, University of Wuerzberg, Wuerzberg, Germany.
Vera
V
Krane
University of British Columbia, Vancouver, BC, Canada.
Adeera
A
Levin
University of Otago, Dunedin, New Zealand.
Robert
R
Walker
Division of Nephrology, University of Wuerzberg, Wuerzberg, Germany.
Christoph
C
Wanner
University College London, London, United Kingdom.
David C
DC
Wheeler
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
Martin J
MJ
Landray
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom. Electronic address: colin.baigent@ctsu.ox.ac.uk.
Colin
C
Baigent
Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom. Electronic address: jonathan.emberson@ctsu.ox.ac.uk.
Jonathan
J
Emberson
D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality; D018450:Disease Progression; D005260:Female; D006331:Heart Diseases / Q000209:etiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D012907:Smoking / Q000009:adverse effects*
Cigarette smoking; Study of Heart and Renal Protection (SHARP); cancer; cause-specific mortality; chronic kidney disease (CKD); disease progression; end-stage renal disease (ESRD); estimated glomerular filtration rate (eGFR); risk factor; tobacco; vascular events; vascular morbidity