Smoking is associated with insulin resistance and cardiovascular autonomic dysfunction in type 2 diabetic patients

BACKGROUND: Smoking and cardiovascular autonomic dysfunction are associated with high mortality in type 2 diabetic patients. This study tested the hypothesis that smoking is associated with insulin resistance/hyperinsulinaemia and cardiovascular autonomic dysfunction in type 2 diabetic patients who are not treated with insulin. MATERIALS AND METHODS: The study patients were 22 current smokers with type 2 diabetes mellitus (age: 57 +/- 5 years, mean +/- SD) and 30 age-matched never-smoked patients with type 2 diabetes mellitus (control group, 57 +/- 8 years). The quality of blood glucose was assessed by fasting plasma glucose (FPG), fasting immunoreactive insulin (F-IRI), homeostasis model assessment (HOMA) index and haemoglobin A1c (HbA1c). The severity of smoking status was expressed by the Brinkman index, which is calculated as number of cigarettes per day multiplied by years of smoking. Cardiovascular autonomic function was assessed by baroreflex sensitivity (BRS), heart-rate variability, plasma norepinephrine concentration and cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphic findings. RESULTS: Baroreflex sensitivity was lower in the current smokers group than in the never-smoked group (P < 0.05). Early and delayed (123)I-MIBG myocardial uptake values were lower (P < 0.05, and P < 0.01, respectively) and the percentage washout-rate of (123)I-MIBG was higher (P < 0.0001) in the current smokers group than in the never-smoked group. Fasting immunoreactive insulin (F-IRI) concentration (P < 0.0001) and the homeostasis model assessment (HOMA) index (P < 0.0001) were higher in the current smokers group than the never-smoked group. Multiple logistic regression analysis revealed that smoking was independently predicted by F-IRI and the percentage washout-rate of (123)I-MIBG. CONCLUSIONS: The results of the study suggested that smoking was associated with cardiovascular autonomic dysfunction and hyperinsulinaemia and that F-IRI and the percentage washout-rate of (123)I-MIBG were independent predictors of smoking in these Japanese patients with type 2 diabetes mellitus.     

Smoking and incidence of diabetes among U.S. adults: findings from the Insulin Resistance Atherosclerosis Study

OBJECTIVE: The objective of this study was to determine the association between smoking and incident diabetes among U.S. adults. RESEARCH DESIGN AND METHODS: The Insulin Resistance Atherosclerosis Study (IRAS) was a prospective study of the associations of insulin sensitivity and cardiovascular risk factors. We examined the relationship between smoking status categories (never, former, and current) and incident 5-year type 2 diabetes among 906 participants free of diabetes at baseline. We also considered the effect of pack-year categories (never, former <20 pack-years, former > or = 20 pack-years, current <20 pack-years, and current > or = 20 pack-years) upon diabetes incidence. RESULTS: Of current smokers, 96 (25%) developed diabetes at 5 years, compared with 60 (14%) never smokers. After multivariable adjustment, current smokers exhibited increased incidence of diabetes compared with never smokers (odds ratio [OR] 2.66, P = 0.001). Similar results were found among current smokers with > or = 20 pack-years with normal glucose tolerance (5.66, P = 0.001). CONCLUSIONS: Smoking shares a robust association with incident diabetes, supporting the current Surgeon General's warnings against cigarette smoking.     

Prevalence of tobacco smoking among urban population of Samara and causative factors

AIM: To examine prevalence and intensity of smoking among general population of Samara, physicians and students of Samara Medical University; to study dependence of this prevalence on different social factors. MATERIAL AND METHODS: A representative sample of adult population was selected by the lists of outpatients of Samara outpatient clinic. The study enrolled 2931 outpatients (1272 males, 1659 females aged 15 years and older)--3.95% of all Samara outpatients. The questionnaire survey covered 360 physicians aged 28-57 years (the response 96.5%), 652 senior medical students aged 21-24 years (the response 93.14%). The results were processed with the statistical computer program BIOSTAT. RESULTS: The percentage of smoking men among 15-19-year-olds was 42.94%, 20-29-year-olds--59.29% (p < 0.01), 30-39-year-olds--62.18%, 60-year-olds and older--35.64%. This proportion for smoking women was 15.04%, 27.11% (p < 0.01), 22.92%, 9.06% (p < 0.001), 5.04%, respectively. Among male physicians smokers were 47.37% (14.29% smoked less than 10 cigarettes, 50.79%--10-20 cigarettes, 34.92%--more than 20 cigarettes a day); 16.54% male physicians smoked earlier, 36.09% never smoked. Relevant percentage for female physicians was 25.99 (38.98, 47.46, 13.56, 13.66 and 60.35, respectively). Among male medical students smokers were 58.6% (29.2% less than 10 cigarettes a day, 55.8%--0-20, 14.9%--more than 20 cigarettes a day); 9.1% smoked earlier, 32.3% never smoked. Among female medical students smokers were 20.3% (70.9, 21.5, 7.6, 9.3 and 70.4%, respectively). CONCLUSION: Tobacco smoking depends on education and marital status. Both in men and women the least number of smokers are among persons with higher education and married ones.     

Chronic cigarette smoking is associated with increased plasma circulating intercellular adhesion molecule 1 levels in young type 1 diabetic patients.

OBJECTIVE: The purposes of this study were to compare plasma concentrations of circulating intercellular adhesion molecule 1 (cICAM-1), a marker of endothelial dysfunction, in nondiabetic subjects and type 1 diabetic patients and to evaluate whether chronic cigarette smoking had a deleterious effect on plasma cICAM-1 levels in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: Plasma cICAM-1 concentrations were measured in 54 young type 1 diabetic patients without clinical macroangiopathy and in 20 healthy control subjects who were matched for age, sex, BMI, and smoking habit. RESULTS: Type 1 diabetic patients had significantly higher plasma levels of cICAM-1 than control subjects (280.4 +/- 59 vs. 224 +/- 53.6 ng/ml, respectively) (P < 0.001). After stratification by smoking status, diabetic smokers had values for age, sex, BMI, lipids, blood pressure, glycemic control, diabetes duration, and chronic complications of diabetes that were super-imposable on their nonsmoking counterparts. Nevertheless, plasma cICAM-1 levels were markedly elevated in type 1 diabetic smokers (321.4 +/- 64.2 vs. 257.3 +/- 41.5 ng/ml, respectively) (P < 0.001) in a dose-dependent fashion (P < 0.001 by analysis of variance when subjects were categorized by number of cigarettes smoked per day). CONCLUSIONS: Chronic cigarette smoking has a deleterious effect on plasma cICAM-1 levels in young type 1 diabetic patients, which further supports the clinical importance of discouraging the initiation of smoking and promoting its cessation in people with type 1 diabetes.     

A prospective study of obesity and risk of coronary heart disease among diabetic women

OBJECTIVE: To examine the relationship of obesity, measured as BMI, and weight change to incidence of coronary heart disease (CHD) among women with diabetes. RESEARCH DESIGN AND METHODS: We followed 5,897 women with type 2 diabetes in the Nurses' Health Study for < or = 20 years. Women were aged 40-74 years and had no history of cardiovascular disease or cancer at the beginning of the follow-up period. BMI values from three time points (age 18 years, year 1976, and current) were derived from the reported height (1976) and corresponding reported weight. Weight changes between age 18 years and 1976 and after diagnosis of diabetes were calculated. Women reported diagnoses of diabetes and CHD every 2 years. Incident CHD cases were confirmed by medical record review. RESULTS: During follow-up, we documented 418 incident cases of CHD (236 of nonfatal myocardial infarction and 182 of fatal CHD). After adjustment for age, smoking, and other coronary risk factors, current BMI was strongly associated with increased risk of CHD among diabetic women. The multivariate relative risks across increasing categories of BMI (<23.0, 23.0-24.9, 25.0-26.9, 27.0-29.9, 30.0-34.9, and > or = 35.0 kg/m(2)) were 1.0, 1.58, 1.85, 1.95, 2.80, and 3.21, respectively (P for trend <0.001). Increasing BMI values from age 18 years to 1976, before diagnosis of diabetes, were also positively associated with risk of CHD. Weight gain before the diagnosis of diabetes was related to increased risk of CHD. In contrast, weight change after diagnosis of diabetes was not associated with risk of CHD. CONCLUSIONS: These findings provide strong evidence that obesity and weight gain before diagnosis of diabetes are associated with future risk of CHD among women with type 2 diabetes.     

Smoking and diabetes mellitus. Findings from 1988 Behavioral Risk Factor Surveillance System.

OBJECTIVE: To examine the association between smoking and self-reported diabetes mellitus. RESEARCH DESIGN AND METHODS: The study was comprised of 3006 people greater than or equal to 18 yr of age with diabetes and 52,750 without diabetes. RESULTS: Twenty-six percent (SE 1.8) of the diabetic population were current smokers, 25.9% (SE 1.4) were former smokers, and 48.1% (SE 2) had never smoked. Similar percentages were found among the nondiabetic population. Compared to respondents without diabetes, the prevalence of current smoking was notably higher among respondents with diabetes who were between the ages of 18 and 34 yr (36.1%, SE 4.1), who had not graduated from high school (44.9%, SE 3.7), and who were men of African-American origin (54.8%, SE 5.8). CONCLUSIONS: Despite the excess risks, the overall prevalence of smoking in the diabetic population is comparable to that of the general population. Our finding of a higher prevalence of smoking among young people, people who had not graduated from high school, and African-American men with diabetes suggests that additional educational efforts should be targeted at these groups.     

Cigarettes smoking habit may reduce benefit from cetuximab-based treatment in advanced colorectal cancer patients

Background: NF-κB is one of the nuclear effectors of EGFR activation. There are reports showing that NF-κB expression and activity is enhanced after nicotine treatment. Some data demonstrated that NF-κB activation plays a role in the induction of resistance to cetuximab and irinotecan in advanced colorectal tumors. The aim of this study was to evaluate the effect of cigarette smoking on cetuximab efficacy in advanced colorectal cancer patients. Methods: We retrospectively analysed the smoking habits of 200 patients treated with a variety of anticancer regimens containing cetuximab for advanced colorectal cancer. All patients were irinotecan-resistant and received an oxaliplatin-based first line treatment. We divided our patient population as follows: no previous smoking habit, previous smokers (any number of cigarettes), current smokers of less of 10 cigarettes/day, current smokers of more than 10 cigarettes/day. Results: Out of 200 patients 58 declared a history of cigarette smoking, 108 patients never smoked and the remaining 44 patients were cigarette smokers during cetuximab-based anticancer therapy. Of the 44 smokers, 18 smoked more than 10 cigarettes per day. No statistically significant differences in terms of response rate (RR) and time to progression (TTP) were identified between previous smokers and never smokers. RR in actual smokers was 13.6% and was lower than RR reported for non-smokers (27.1%; p = 0.023). In addition, the median TTP was 5.5 months in the non-smokers versus 2.8 months in the current smokers (p < 0.0001). A difference in terms of overall survival (OS) was detected between the two groups (p = 0.03). Comparing smokers of more than 10 cigarettes per day and smokers of less than 10 cigarettes per day no differences were detected in RR, TTP or OS. Conclusions: Our results suggest that cigarette smoking during anticancer treatment with a cetuximab-based regimen may be responsible for a decrease in RR and lead to a lower TTP.     

Smoking status, obesity and hypertension in a general population sample: a cross-sectional study

BACKGROUND: In some studies, hypertension is more common in never and former smokers than in current smokers. AIM: To examine the associations between hypertension and smoking status, when divided into subgroups by overweight and obesity. DESIGN: Cross-sectional study. METHODS: We used data from a national health survey with a probability sample of the national population of Germany aged 18 to 79 (n = 6903 with complete data). Smoking status data were collected via questionnaire. Obesity and overweight were assessed by body mass index, hypertension by blood pressure measurement and by participants' statements about antihypertensive treatment. Analyses were adjusted for gender, age, history of coronary artery disease, serum cholesterol levels, alcohol drinking, exercise, and education. RESULTS: Obese former smokers who were abstinent for 3 or more years had an adjusted odds ratio (OR) 3.6 (95% confidence interval, CI 2.3-5.7) for mild hypertension (> or =140 mmHg systolic or > or =90 mmHg diastolic blood pressure) and an adjusted OR 6.5 (95%CI 3.6-11.8) for moderate or severe hypertension (> or =160 mmHg systolic or > or =100 mmHg diastolic). Normal weight never or former smokers did not differ from normal weight current smokers smoking > or =15 cigarettes/day with regard to likelihood of hypertension (normal weight never smokers, OR 1.1, 95%CI 0.8-1.5; normal weight former smokers, abstinent 3 or more years, OR 0.8, 95%CI 0.5-1.3). DISCUSSION: In this nationally representative sample, never or former smoking was unrelated to hypertension among normal weight individuals.     

Cigarette smoking and plasma total homocysteine levels in young adults with type 1 diabetes

OBJECTIVE: The purposes of this study were to compare plasma total homocysteine (tHcy) levels, a recognized cardiovascular risk factor, in nondiabetic subjects and type 1 diabetic patients, and to evaluate whether chronic cigarette smoking had a deleterious effect on plasma tHcy levels in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: Plasma tHcy concentrations were measured in 60 young type 1 diabetic patients without clinical evidence of macroangiopathy and in 30 healthy control subjects who were matched for age, sex, BMI, and smoking habit. RESULTS: Plasma tHcy levels were significantly higher in type 1 diabetic patients than in control subjects (12.5 +/- 4.8 vs. 10.3 +/- 2.2 micromol/l, P = 0.01). After stratification by smoking status, diabetic smokers had values for age, sex, BMI, lipids, creatinine, blood pressure, glycometabolic control, diabetes duration, and microvascular complications that were superimposable on their nonsmoking counterparts. Nevertheless, plasma tHcy levels were markedly elevated in diabetic smokers versus nonsmokers (15.5 +/- 5.7 vs. 10.6 +/- 3 pmol/l, P < 0.0001) in a dose-dependent fashion (P < 0.0001, by analysis of variance when subjects were categorized for the number of cigarettes smoked daily). CONCLUSIONS: Chronic cigarette smoking seems to adversely affect plasma tHcy levels in young adults with type 1 diabetes.     

A prospective study of soluble tumor necrosis factor-alpha receptor II (sTNF-RII) and risk of coronary heart disease among women with type 2 diabetes

OBJECTIVE: Tumor necrosis factor-alpha (TNF-alpha), a cytokine secreted by adipose tissue and other cells, might play a role in insulin resistance. RESEARCH DESIGN AND METHODS: Of 32,826 women from the Nurses' Health Study who provided blood at baseline, we followed 929 women with type 2 diabetes. During 10 years of follow-up, we documented 124 incident cases of coronary heart disease (CHD). RESULTS: After adjustment for age, smoking, BMI, and other cardiovascular risk factors, the relative risks (RRs) comparing extreme quartiles of soluble TNF-alpha receptor II (sTNF-RII) were 2.48 (95% CI 1.08-5.69; P = 0.034) for myocardial infarction (MI) and 2.02 (1.17-3.48; P = 0.003) for total CHD. The probability of developing CHD over 10 years was higher among diabetic subjects with substantially higher levels of both sTNF-RII (>75th percentile) and HbA(1c) (>7%), compared with diabetic subjects with lower levels (25% vs. 7%, P < 0.0001). Diabetic subjects with only higher sTNF-RII or HbA(1c) had similar (16-17%) risk. In a multivariate model, diabetic subjects with higher levels of both sTNF-RII and HbA(1c) had an RR of 3.66 (1.85-7.22) for MI and 3.03 (1.82-5.05) for total CHD, compared with those with lower levels of both biomarkers. CONCLUSIONS: Increased levels of sTNF-RII were strongly associated with risk of CHD among diabetic women, independent of hyperglycemia.     

The smoking behaviour of military nurses: the relationship to job stress, job satisfaction and social support

Three hundred and seven nurses at a large military medical centre were sent and completed an anonymous questionnaire which measured their smoking status along with job stress, job satisfaction and social support, as well as a variety of demographic factors. Three groups of nurses were defined on the basis of their response to the smoking status questions: those who have never smoked (54%), former smokers (23%) and current smokers (22%). The results revealed that the current smokers reported significantly (P less than 0.05) more job stress, job dissatisfaction and less social support than either former smokers or those who had never smoked. Further, the former smokers reported significantly less social support, defined from a variety of perspectives, than those who had never smoked. These were not as important in predicting amount smoked (number of cigarettes per day) among the current smoker group as they were in predicting differences between the different smoking status groups. The results suggest the need to incorporate the issues of social support and to a lesser extent job stress/satisfaction issues into smoking cessation programmes aimed at this population.     

Cigarette smoking is associated with low glomerular filtration rate in male patients with type 2 diabetes

OBJECTIVE: The relationship between cigarette smoking and renal dysfunction in diabetes has predominantly been documented in patients with type 1 diabetes. The aim of the present study was to explore the relationship between cigarette smoking and glomerular filtration rate (GFR) in a large cross-sectional study carried out in male subjects with type 2 diabetes. The role of metabolic syndrome in modulating this relationship was also investigated. RESEARCH DESIGN AND METHODS: One hundred fifty-eight current smokers and 158 never smokers with type 2 diabetes were consecutively recruited. Low GFR was defined as GFR <60 ml/min per 1.73 m(2). RESULTS: The proportion of patients affected by low GFR was significantly higher in current smokers (20.9 vs. 12.0%, P = 0.03). The adjusted risk (odds ratio [OR]) of low GFR in current smokers was 2.20 (95% CI 1.14-4.26, P = 0.02) and markedly higher in patients from the first tertile of disease duration (4.27 [1.26-14.40], P = 0.02). When metabolic syndrome was added to the statistical model exploring the relationship between smoking and low GFR, the risk of low GFR showed a small change, although it did not become any more significant (1.84 [0.98-3.45], P = 0.06). Current smokers showed even higher free oxygen radical test unit values (560.0 +/- 91.5 vs. 442.7 +/- 87.2, P < 0.0001). CONCLUSIONS: In a large population of male patients with type 2 diabetes, the risk of low GFR is markedly enhanced by smoking and is at least partially mediated by metabolic syndrome.     

Cigarette smoking and the risk of gestational and pregestational diabetes in two consecutive pregnancies

OBJECTIVE: Cigarette smoking during pregnancy may increase the risk of gestational diabetes mellitus (GDM) or pregestational diabetes mellitus (PDM). Smoking has been associated positively with hyperinsulinemia and insulin resistance in experimental studies, although the association with diabetes remains unclear. To further explore this issue, we examined the association with smoking in the largest prospective cohort study of GDM and PDM to date. RESEARCH DESIGN AND METHODS: The study population comprised 212190 women in the population-based Swedish Birth Registry who had their first and second deliveries between January 1987 and December 1995. Maternal characteristics were recorded in a standardized manner at the first prenatal visit, followed by a clinical examination and a standardized in-person interview to assess lifestyle habits. Women were categorized as nonsmokers, light smokers (one to nine cigarettes per day), or moderate-to-heavy smokers (at least 10 cigarettes per day). RESULTS: Women with GDM in their first pregnancy experienced an eight- to ninefold increased risk of GDM or PDM in their second pregnancy. Cigarette smoking was not associated with increased risk of these conditions. Neither women who smoked during their first and second pregnancies nor those who commenced smoking between pregnancies had a higher risk of GDM or PDM than nonsmokers. CONCLUSIONS: Our findings do not support an association between cigarette smoking and risk of GDM or PDM in young women of childbearing age.     

Depressive symptomatology and smoking among persons with diabetes

The purpose of this study was to determine whether (a) symptoms of depression are more prevalent and severe among diabetic smokers than diabetic nonsmokers, (b) smoking is related to depressive symptomatology among diabetic patients, and (c) there is a positive relationship between number of cigarettes smoked and severity of depressive symptoms. Diabetic non-smokers (n = 103) and diabetic smokers (n = 83) were surveyed regarding symptoms of depression as measured by the Beck Depression Inventory (BDI). Depressive symptomatology was more prevalent and severe among smokers than nonsmokers. Smoking was significantly associated with depressive symptomatology. Among smokers, the number of cigarettes smoked per day was independently associated with cognitive symptoms of depression.     

Intervention study for smoking cessation in diabetic patients: a randomized controlled trial in both clinical and primary care settings

OBJECTIVE: To evaluate the effectiveness of a nurse-managed smoking cessation intervention in diabetic patients. RESEARCH DESIGN AND METHODS: This randomized controlled clinical trial involved 280 diabetic smokers (age range 17-84 years) who were randomized either into control (n = 133) or intervention (n = 147) groups at 12 primary care centers and 2 hospitals located in Navarre, Spain. The intervention consisted of a 40-min nurse visit that included counseling, education, and contracting information (a negotiated cessation date). The follow-up consisted of telephone calls, letters, and visits. The control group received the usual care for diabetic smokers. Baseline and 6-month follow-up measurements included smoking status (self-reported cessation was verified by urine cotinine concentrations), mean number of cigarettes smoked per day, and stage of change. RESULTS: At the 6-month follow-up, the smoking cessation incidence was 17.0% in the intervention group compared with 2.3% in the usual care group, which was a 14.7% difference (95% CI 8.2-21.3%). Among participants who continued smoking, a significant reduction was evident in the average cigarette consumption at the 6-month follow-up. The mean number of cigarettes per day decreased from 20.0 at baseline to 15.5 at 6 months for the experimental group versus from 19.7 to 18.1 for the control group (P < 0.01). CONCLUSIONS: A structured intervention managed by a single nurse was shown to be effective in changing the smoking behavior of diabetic patients.     

Type 2 diabetes and cognitive function in community-dwelling elderly women

OBJECTIVE--To examine the relationship of type 2 diabetes to cognitive function in community-dwelling women. RESEARCH DESIGN AND METHODS--From 1995 to 1999, we administered four tests of cognitive function (Telephone Interview of Cognitive Status [TICS], immediate and delayed recall of the East Boston Memory Test, and verbal fluency) by telephone to 2,374 participants (70-78 years of age) of the Nurses' Health Study. Information on diabetes was collected biennially beginning in 1976; 82 women reported type 2 diabetes before their cognitive testing. We used linear and logistic regression models to calculate multivariate-adjusted mean differences in scores and relative risks of a low score (bottom 10% of the distribution) for diabetic women compared with nondiabetic women. RESULTS--After multivariate adjustment, women with type 2 diabetes scored lower on all our cognitive tests than women without diabetes. On the general test of cognition (TICS), the mean difference in score between women with and without diabetes was -0.60 (95% CI -1.18 to -0.03, P = 0.04) and the relative risk of a low TICS score was 1.98 (95% CI 1.06 to 3.69). On a global score combining results of the four tests, the mean for diabetic women was lower than that among women without diabetes (adjusted difference in score -0.73, 95% CI -1.42 to -0.04, P = 0.04), and the relative risk of a low global score was 2.16 (95% CI 1.10 to 4.21). Relative to women without diabetes, longer duration of diabetes was associated with lower scores. Few diabetic women were pharmacologically treated (n = 31), but those taking medication had scores similar to those of women without diabetes. CONCLUSIONS--In these women, diabetes was related to lower scores on several aspects of cognitive function. Longer duration of diabetes may be associated with poorer scores, but hypoglycemic therapy may ameliorate scores.     

Coffee, caffeine, and risk of type 2 diabetes: a prospective cohort study in younger and middle-aged U.S. women

OBJECTIVE: High habitual coffee consumption has been associated with a lower risk of type 2 diabetes, but data on lower levels of consumption and on different types of coffee are sparse. RESEARCH DESIGN AND METHODS: This is a prospective cohort study including 88,259 U.S. women of the Nurses' Health Study II aged 26-46 years without history of diabetes at baseline. Consumption of coffee and other caffeine-containing foods and drinks was assessed in 1991, 1995, and 1999. We documented 1,263 incident cases of confirmed type 2 diabetes between 1991 and 2001. RESULTS: After adjustment for potential confounders, the relative risk of type 2 diabetes was 0.87 (95% CI 0.73-1.03) for one cup per day, 0.58 (0.49-0.68) for two to three cups per day, and 0.53 (0.41-0.68) for four or more cups per day compared with nondrinkers (P for trend <0.0001). Associations were similar for caffeinated (0.87 [0.83-0.91] for a one-cup increment per day) and decaffeinated (0.81 [0.73-0.90]) coffee and for filtered (0.86 [0.82-0.90]) and instant (0.83 [0.74-0.93]) coffee. Tea consumption was not substantially associated with risk of type 2 diabetes (0.88 [0.64-1.23] for four or more versus no cups per day; P for trend = 0.81). CONCLUSIONS: These results suggest that moderate consumption of both caffeinated and decaffeinated coffee may lower risk of type 2 diabetes in younger and middle-aged women. Coffee constituents other than caffeine may affect the development of type 2 diabetes.     

Type 2 diabetes and subsequent incidence of breast cancer in the Nurses' Health Study

OBJECTIVE: Hyperinsulinemia may promote mammary carcinogenesis. Insulin resistance has been linked to an increased risk of breast cancer and is also characteristic of type 2 diabetes. We prospectively evaluated the association between type 2 diabetes and invasive breast cancer incidence in the Nurses' Health Study. RESEARCH DESIGN AND METHODS: A total of 116,488 female nurses who were 30-55 years old and free of cancer in 1976 were followed through 1996 for the occurrence of type 2 diabetes and through 1998 for incident invasive breast cancer, verified by medical records and pathology reports. RESULTS: During 2.3 million person-years of follow-up, we identified 6,220 women with type 2 diabetes and 5,189 incident cases of invasive breast cancer. Women with type 2 diabetes had a modestly elevated incidence of breast cancer (hazard ratio [HR] = 1.17; 95% CI 1.01-1.35) compared with women without diabetes, independent of age, obesity, family history of breast cancer, history of benign breast disease, reproductive factors, physical activity, and alcohol consumption. This association was apparent among postmenopausal women (1.16; 0.98-1.62) but not premenopausal women (0.83; 0.48-1.42). The association was predominant among women with estrogen receptor-positive breast cancer (1.22; 1.01-1.47). CONCLUSIONS: Women with type 2 diabetes may have a slightly increased risk of breast cancer.     

Association between passive and active smoking and incident type 2 diabetes in women

OBJECTIVE

Accumulating evidence has identified a positive association between active smoking and the risk of diabetes, but previous studies had limited information on passive smoking or changes in smoking behaviors over time. This analysis examined the association between exposure to passive smoke, active smoking, and the risk of incident type 2 diabetes among women.

RESEARCH DESIGN AND METHODS

This is a prospective cohort study of 100,526 women in the Nurses’ Health Study who did not have prevalent diabetes in 1982, with follow-up for diabetes for 24 years.

RESULTS

We identified 5,392 incident cases of type 2 diabetes during 24 years of follow-up. Compared with nonsmokers with no exposure to passive smoke, there was an increased risk of diabetes among nonsmokers who were occasionally (relative risk [RR] 1.10 [95% CI 0.94–1.23]) or regularly (1.16 [1.00–1.35]) exposed to passive smoke. The risk of incident type 2 diabetes was increased by 28% (12–50) among all past smokers. The risk diminished as time since quitting increased but still was elevated even 20–29 years later (1.15 [1.00–1.32]). Current smokers had the highest risk of incident type 2 diabetes in a dose-dependent manner. Adjusted RRs increased from 1.39 (1.17–1.64) for 1–14 cigarettes per day to 1.98 (1.57–2.36) for ≥25 cigarettes per day compared with nonsmokers with no exposure to passive smoke.

CONCLUSIONS

Our study suggests that exposure to passive smoke and active smoking are positively and independently associated with the risk of type 2 diabetes.Smoking is one of the leading causes of avoidable death globally (1). The disease burden attributable to smoking already is enormous, with ~6 million premature deaths worldwide each year, and is projected to grow substantially across the century without an end to the pandemic (1). Diabetes also is a global health priority. The International Diabetes Federation has predicted that the number of individuals with diabetes will increase from 240 million in 2007 to 380 million in 2025 (2).Accumulating evidence has identified a positive association between active smoking and risk of type 2 diabetes (3), whereas few studies had information on passive smoking. Data from the Third National Health and Nutrition Examination Survey 1988–1991 suggest that ~90% of nonsmokers have detectable levels of serum cotinine, a sensitive marker for tobacco exposure (4). Therefore, previous studies linking active smoking with diabetes risk might have underestimated the magnitude of the true association because individuals exposed to passive smoke would be in the reference group. The few studies that simultaneously examined the relative associations of passive and active smoking on diabetes risk (5,6) were limited by relatively short follow-up periods, limited information on potential confounders, and lack of information on smoking quantity or change in smoking behavior over time. Therefore, we prospectively investigated the association between passive and active smoking and the risk of incident type 2 diabetes over 24 years of follow-up among 100,526 women from the Nurses’ Health Study (NHS).