Table 2.
Pooled Hazard Ratios for Association between Smoking Cessation and the Incidence of Type 2 Diabetes, Death from Cardiovascular Disease, and Death from Any Cause.*
| Variable | Cases/Person-yr | Hazard Ratio (95% CI) | ||
|---|---|---|---|---|
| Adjusted for Age |
Adjusted for Baseline BMI |
Adjusted for Multiple Variables |
||
| Type 2 diabetes | ||||
| Current smokers | 1,547/395,872 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| Recent quitters† | 836/148,082 | 1.35 (1.24–1.47)‡ | 1.25 (1.14–1.36)‡ | 1.22 (1.12–1.32)‡ |
| No weight gain | 204/37,444 | 1.27 (1.10–1.48) ‡ | 1.09 (0.94–1.27) | 1.08 (0.93–1.26) |
| Weight gain of 0.1–5.0 kg | 206/52,147 | 0.96 (0.83–1.11) | 1.14 (0.99–1.32) | 1.15 (0.99–1.33) |
| Weight gain of 5.1–10.0 kg | 188/29,767 | 1.52 (1.30–1.77)‡ | 1.44 (1.23–1.68)‡ | 1.36 (1.16–1.58)‡ |
| Weight gain of >10.0 kg | 196/19,424 | 2.58 (2.22–2.99)‡ | 1.66 (1.43–1.94)‡ | 1.59 (1.36–1.85)‡ |
| Long-term quitters | 1,168/185,838 | 1.15 (1.07–1.25)‡ | 1.03 (0.96–1.12) | 1.02 (0.94–1.10) |
| Transient quitters | 54/12,853 | 1.12 (0.85–1.47) | 1.09 (0.83–1.44) | 1.09 (0.83–1.44) |
| Never smoked | 8,779/2,451,805 | 0.91 (0.86–0.96)‡ | 0.77 (0.72–0.81)‡ | 0.72 (0.68–0.76)‡ |
| Death from cardiovascular disease§ | ||||
| Current smokers | 1,488/524,182 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| Recent quitters† | 167/154,259 | 0.44 (0.37–0.51)‡ | 0.44 (0.37–0.51)‡ | 0.48 (0.41–0.56)‡ |
| No weight gain | 68/39,637 | 0.63 (0.49–0.80)‡ | 0.63 (0.49–0.80)‡ | 0.69 (0.54–0.88)‡ |
| Weight gain of 0.1–5.0 kg | 46/53,969 | 0.39 (0.29–0.52)‡ | 0.41 (0.31–0.55)‡ | 0.47 (0.35–0.63)‡ |
| Weight gain of 5.1–10.0 kg | 14/30,926 | 0.23 (0.14–0.39)‡ | 0.23 (0.14–0.40)‡ | 0.25 (0.15–0.42)‡ |
| Weight gain of >10.0 kg | 11/20,670 | 0.36 (0.20–0.65)‡ | 0.32 (0.18–0.59)‡ | 0.33 (0.18–0.60)‡ |
| Long-term quitters | 656/256,194 | 0.46 (0.42–0.51)‡ | 0.46 (0.42–0.50)‡ | 0.50 (0.46–0.55)‡ |
| Never smoked | 3,181/3,003,966 | 0.34 (0.32–0.36)‡ | 0.31 (0.29–0.33)‡ | 0.34 (0.32–0.37)‡ |
| Death from any cause§ | ||||
| Current smokers | 6,537/519,569 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| Recent quitters† | 880/153,642 | 0.53 (0.49–0.57)‡ | 0.53 (0.49–0.57)‡ | 0.58 (0.54–0.62)‡ |
| No weight gain | 360/39,386 | 0.75 (0.67–0.83)‡ | 0.74 (0.67–0.83)‡ | 0.81 (0.73–0.90)‡ |
| Weight gain of 0.1–5.0 kg | 236/53,815 | 0.44 (0.39–0.51)‡ | 0.46 (0.40–0.52)‡ | 0.52 (0.46–0.59)‡ |
| Weight gain of 5.1–10.0 kg | 115/30,826 | 0.42 (0.35–0.50)‡ | 0.42 (0.35–0.51)‡ | 0.46 (0.38–0.55)‡ |
| Weight gain of >10.0 kg | 76/20,616 | 0.51 (0.40–0.64)‡ | 0.48 (0.38–0.61)‡ | 0.50 (0.40–0.63)‡ |
| Long-term quitters | 3,252/253,822 | 0.50 (0.48–0.53)‡ | 0.50 (0.48–0.52)‡ | 0.57 (0.54–0.59)‡ |
| Never smoked | 13,198/2,994,849 | 0.32 (0.31–0.33)‡ | 0.31 (0.30–0.32)‡ | 0.35 (0.34–0.37)‡ |
Hazard ratios and 95% confidence intervals (CIs) were estimated with the use of a Cox proportional-hazards model. Multivariate analyses were adjusted for age (in months, continuous), cohort (Nurses’ Health Study, Nurses’ Health Study II, or Health Professionals Follow-up Study), sex (male or female), race (white, black, Asian, or other), physical activity (in quintiles), baseline body-mass index (BMI, in continuous and quadratic terms), alcohol intake (0, <5.0, 5.0 to 9.9, 10.0 to 14.9, 15.0 to 29.9, or >30.0 g per day), hypertension (yes or no), hypercholesterolemia (yes or no), family history of diabetes (yes or no), multivitamin use (yes or no), Alternative Healthy Eating Index score (in quintiles), and total energy intake (in quintiles). Hazard ratios for death from cardiovascular disease and death from any cause were also adjusted for family history of myocardial infarction (yes or no).
In analyses involving recent quitters with stratification according to weight change since quitting, 0.3% of the cases (42 cases) and 0.3% of the person-time in the analysis of type 2 diabetes, 0.1% of the cases (28 cases) and 0.2% of the person-time in the analysis of death from cardiovascular disease, and 0.4% of the cases (93 cases) and 0.3% of the person-time in the analysis of death from any cause with missing data regarding weight change were removed from the stratified analyses, and therefore the total number of cases and total person-time across weight-change categories were smaller than those in the analyses involving total recent quitters, without consideration of subsequent weight change.
The false discovery rate was less than 0.05.
There were no cases among transient quitters for the analyses of death from cardiovascular disease and death from any cause.