cutting smoking in half no effect on mortality morbidity

 

Tob Control. 2006 Dec;15(6):472-80.

Health consequences of reduced daily cigarette consumption.

Tverdal A1, Bjartveit K.

Author information

Abstract

OBJECTIVE:

To determine the risk of dying from specified smoking-related diseases and from any cause in heavy smoking men and women (> or =15 cigarettes/day), who reduced their daily cigarette consumption by >50%.

DESIGN:

A prospective cohort study.

SETTING:

Three counties in Norway.

PARTICIPANTS:

24,959 men and 26,251 women, aged 20-49 years, screened for risk factors of cardiovascular disease in the mid-1970s, screened again after 3-13 years, and followed up throughout 2003.

OUTCOMES:

Absolute mortality and relative risks adjusted for confounding variables, of dying from all causes, cardiovascular disease, ischaemic heart disease, all smoking-related cancer and lung cancer.

RESULTS:

With sustained heavy smokers as reference, the smokers of both sexes who reduced their daily consumption (reducers) had the following adjusted relative risks (95% confidence interval (CI)): of dying from any cause, 1.02 (0.84 to 1.22); cardiovascular disease, 1.02 (0.75 to 1.39); ischaemic heart disease, 0.96 (0.65 to 1.41); smoking-related cancer, 0.86 (0.57 to 1.29); and lung cancer, 0.66 (0.36 to 1.21). The difference in cigarette consumption between two examinations was not a significant predictor of death from any of the causes. A follow-up from a third screening of the subgroup who were reducers at both second and third examinations (sustained reducers) did not have a lower risk than those who were heavy smokers at all three examinations.

CONCLUSIONS:

Long-term follow-up provides no evidence that heavy smokers who cut down their daily cigarette consumption by >50% reduce their risk of premature death significantly. In health education and patient counselling, it may give people false expectations to advise that reduction in consumption is associated with reduction in harm.

PMID:

 

17130377

 

[PubMed - indexed for MEDLINE] 

PMCID:

 

PMC2563668

The long-term effects of a substantial reduction (>50%) in daily cigarette consumption had no effect on all-cause mortality or premature deaths due to cardiovascular disease, smoking-related cancer and respiratory disease. Although the adjusted relative risk of death due to lung cancer was lower, the difference was not statistically significant.⁵ (Table 2-1)

 

Table 2-1. Adjusted relative risk* (RR) of death from all causes and various causes:† reducers vs. continuing heavy smokers.
Both sexes	Reducers‡	Heavy smokers¶
All causes	RR 1.02 (0.84 to 1.22)	1.00
Cardiovascular disease	RR 1.02 (0.75 to 1.39)	1.00
Ischaemic heart disease	RR 0.96 (0.65 to 1.41)	1.00
Smoking-related cancer	RR 0.86 (0.57 to 1.28)	1.00
Lung cancer	RR 0.66 (0.36 to 1.21)	1.00

Running News: Short Distances Count

Background  Although running is a popular leisure-time physical activity, little is known about the long-term effects of running on mortality. The dose-response relations between running, as well as the change in running behaviors over time, and mortality remain uncertain.

Objectives  We examined the associations of running with all-cause and cardiovascular mortality risks in 55,137 adults, 18 to 100 years of age (mean age 44 years).

Methods  Running was assessed on a medical history questionnaire by leisure-time activity.

Results  During a mean follow-up of 15 years, 3,413 all-cause and 1,217 cardiovascular deaths occurred. Approximately 24% of adults participated in running in this population. Compared with nonrunners, runners had 30% and 45% lower adjusted risks of all-cause and cardiovascular mortality, respectively, with a 3-year life expectancy benefit. In dose-response analyses, the mortality benefits in runners were similar across quintiles of running time, distance, frequency, amount, and speed, compared with nonrunners. Weekly running even <51 min, <6 miles, 1 to 2 times, <506 metabolic equivalent-minutes, or <6 miles/h was sufficient to reduce risk of mortality, compared with not running. In the analyses of change in running behaviors and mortality, persistent runners had the most significant benefits, with 29% and 50% lower risks of all-cause and cardiovascular mortality, respectively, compared with never-runners.

Conclusions  Running, even 5 to 10 min/day and at slow speeds <6 miles/h, is associated with markedly reduced risks of death from all causes and cardiovascular disease. This study may motivate healthy but sedentary individuals to begin and continue running for substantial and attainable mortality benefits.