Cigarette smoking, weight gain, and coronary mortality: results from the Chicago Western Electric Study

Estimating the risk of type-2 diabetes using obese-years in a contemporary population of the Framingham Study

Background

We have recently demonstrated that an obese-years construct is a better predictor of the risk of diabetes than the severity of body weight alone. However, these risk estimates were derived from a population cohort study initiated in 1948 that might not apply to the current population.

Objective

To validate an obese-years construct in estimating the risk of type-2 diabetes in a more contemporary cohort study.

Design

A total of 5,132 participants of the Framingham Offspring Study, initiated in 1972, were followed up for 45 years. Body mass index (BMI) above 29 kg/m² was multiplied by the number of years lived with obesity at that BMI to define the number of obese-years. Time-dependent Cox regression was used to explore the association.

Results

The risk of type-2 diabetes increased significantly with increase in obese-years. Adjusted hazard ratios increased by 6% (95% CI: 5–7%) per additional 10 points of obese-years. This ratio was observed to be similar in both men and women, but was 4% higher in current smokers than in never/ex-smokers. The Akaike Information Criterion confirmed that the Cox regression model with the obese-years construct was a stronger predictor of the risk of diabetes than a model including either BMI or the duration of obesity alone.

Conclusions

In a contemporary cohort population, it was confirmed that the obese-years construct is strongly associated with an increased risk of type-2 diabetes. This suggests that both severity and the duration of obesity should be considered in future estimations of the burden of disease associated with obesity.

Psychosocial interventions for smoking cessation in patients with coronary heart disease

BACKGROUND

This is an update of a Cochrane review previously published in 2008. Smoking increases the risk of developing atherosclerosis but also acute thrombotic events. Quitting smoking is potentially the most effective secondary prevention measure and improves prognosis after a cardiac event, but more than half of the patients continue to smoke, and improved cessation aids are urgently required.

OBJECTIVES

This review aimed to examine the efficacy of psychosocial interventions for smoking cessation in patients with coronary heart disease in short-term (6 to 12 month follow-up) and long-term (more than 12 months). Moderators of treatment effects (i.e. intervention types, treatment dose, methodological criteria) were used for stratification.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (Issue 12, 2012), MEDLINE, EMBASE, PsycINFO and PSYNDEX were searched from the start of the database to January 2013. This is an update of the initial search in 2003. Results were supplemented by cross-checking references, and handsearches in selected journals and systematic reviews. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in patients with CHD with a minimum follow-up of 6 months.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and risk of bias. Abstinence rates were computed according to an intention to treat analysis if possible, or if not according to completer analysis results only. Subgroups of specific intervention strategies were analysed separately. The impact of study quality on efficacy was studied in a moderator analysis. Risk ratios (RR) were pooled using the Mantel-Haenszel and random-effects model with 95% confidence intervals (CI).

MAIN RESULTS

We found 40 RCTs meeting inclusion criteria in total (21 trials were new in this update, 5 new trials contributed to long-term results (more than 12 months)). Interventions consist of behavioural therapeutic approaches, telephone support and self-help material and were either focused on smoking cessation alone or addressed several risk factors (eg. obesity, inactivity and smoking). The trials mostly included older male patients with CHD, predominantly myocardial infarction (MI). After an initial selection of studies three trials with implausible large effects of RR > 5 which contributed to substantial heterogeneity were excluded. Overall there was a positive effect of interventions on abstinence after 6 to 12 months (risk ratio (RR) 1.22, 95% confidence interval (CI) 1.13 to 1.32, I² 54%; abstinence rate treatment group = 46%, abstinence rate control group 37.4%), but heterogeneity between trials was substantial. Studies with validated assessment of smoking status at follow-up had similar efficacy (RR 1.22, 95% CI 1.07 to 1.39) to non-validated trials (RR 1.23, 95% CI 1.12 to 1.35). Studies were stratified by intervention strategy and intensity of the intervention. Clustering reduced heterogeneity, although many trials used more than one type of intervention. The RRs for different strategies were similar (behavioural therapies RR 1.23, 95% CI 1.12 to 1.34, I² 40%; telephone support RR 1.21, 95% CI 1.12 to 1.30, I² 44%; self-help RR 1.22, 95% CI 1.12 to 1.33, I² 40%). More intense interventions (any initial contact plus follow-up over one month) showed increased quit rates (RR 1.28, 95% CI 1.17 to 1.40, I² 58%) whereas brief interventions (either one single initial contact lasting less than an hour with no follow-up, one or more contacts in total over an hour with no follow-up or any initial contact plus follow-up of less than one months) did not appear effective (RR 1.01, 95% CI 0.91 to 1.12, I² 0%). Seven trials had long-term follow-up (over 12 months), and did not show any benefits. Adverse side effects were not reported in any trial. These findings are based on studies with rather low risk of selection bias but high risk of detection bias (namely unblinded or non validated assessment of smoking status).

AUTHORS' CONCLUSIONS

Psychosocial smoking cessation interventions are effective in promoting abstinence up to 1 year, provided they are of sufficient duration. After one year, the studies showed favourable effects of smoking cessation intervention, but more studies including cost-effectiveness analyses are needed. Further studies should also analyse the additional benefit of a psychosocial intervention strategy to pharmacological therapy (e.g. nicotine replacement therapy) compared with pharmacological treatment alone and investigate economic outcomes.

Significant interactions between traditional risk factors affect cardiovascular risk prediction in healthy general population

AIMS

The aim was to carry out a systematic screening of interactions between the traditional risk factors and to evaluate which interactions are truly relevant for estimation of cardiovascular disease (CVD) risk.

METHODS

Cox regression was used in a meta-analysis of five independent, population-based health examination surveys (the National FINRISK Study). End-points were 10-year incidence of coronary heart disease (CHD), ischemic stroke (IS), and CVD in a population free of cardiovascular disease (n = 35,460).

RESULTS

In addition to expected age interactions, systolic blood pressure was found to be a markedly stronger risk factor for CVD (and for CHD) among subjects with normal BMI (BMI < 25: HR 1.42 [1.30-1.55] for one SD increase in systolic blood pressure) when compared to obese subjects (BMI > 30: HR 1.10 [1.01-1.19]) (P < 0.001 for interaction) and among subjects with highest high-density lipoprotein (HDL) (33% tertile: HR 1.43 [1.29-1.58]) when compared to subjects with low HDL (lowest 33% tertile: HR 1.20 [1.13-1.28]) (P < 0.001 for interaction). Interactions improved risk prediction of CVD (cross-validated continuous net reclassification improvement [NRI] 49.4% with 95% CI 44.7%-54.1%, P < 0.0001 and clinical NRI 4.7%, with 95% CI 2.8%-6.5%, P < 0.0001). The C-statistic improved from 0.8438 to 0.8455 (P = 0.010). No significant interaction was associated with the risk of IS.

CONCLUSIONS

There are significant effect modifications between major risk factors, and accounting for them leads to significantly more accurate estimation of cardiovascular risk.

Epidemiologic merit of obese-years, the combination of degree and duration of obesity

This study aims to test the effect of combining the degree and the duration of obesity into a single variable-obese-years-and to examine whether obese-years is a better predictor of the risk of diabetes than simply body mass index (BMI) or duration of obesity. Of the original cohort of the Framingham Heart Study, 5,036 participants were followed up every 2 years for up to 48 years (from 1948). The variable, obese-years, was defined by multiplying for each participant the number of BMI units above 30 kg/m(2) by the number of years lived at that BMI. Associations with diabetes were analyzed by using time-dependent Cox proportional hazards regression models adjusted for potential confounders. The incidence of type-2 diabetes increased as the number of obese-years increased, with adjusted hazard ratios of 1.07 (95% confidence interval: 1.06, 1.09) per additional 10 obese-years. The dose-response relation between diabetes incidence and obese-years varied by sex and smoking status. The Akaike Information Criterion was lowest in the model containing obese-years compared with models containing either the degree or duration of obesity alone. A construct of obese-years is strongly associated with risk of diabetes and could be a better indicator of the health risks associated with increasing body weight than BMI or duration of obesity alone.

Association of changes in body mass index during earlier adulthood and later adulthood with circulating obesity biomarker concentrations in middle-aged men and women

AIMS/HYPOTHESIS

The objective of our study was to investigate whether changes in BMI during earlier adulthood are more strongly associated with levels of circulating obesity biomarkers in middle age than are BMI changes during later adulthood.

METHODS

The study included 1,612 participants from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. The associations of BMI changes based on recalled BMI for the age ranges 25-40 years (earlier adulthood) and 40-55 years (later adulthood) with later biomarker levels were compared using a linear model, adjusted for BMI at age 25 years and conventional risk factors.

RESULTS

BMI changes during both time periods as well as BMI at age 25 years were significantly associated with circulating levels of adiponectin, γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), high-sensitivity C-reactive protein (hs-CRP) and HDL-cholesterol (HDL-C) in both sexes, and of HbA(1c) in women. However, BMI gain for the age range 25-40 years was significantly more strongly associated with unfavourable levels of adiponectin, hs-CRP, HDL-C and HbA(1c) in men and women, and of GGT and ALT in men (p difference <0.05) than BMI gain for the age range 40-55 years. The percentage change in biomarker levels per unit gain in BMI for the age range 25-40 years ranged from 0.81% (HbA(1c)) to 9.80% (hs-CRP) in men, and from 0.75% (HbA(1c)) to 14.7% (hs-CRP) in women, whereas for the age range 40-55 years, values ranged from -0.15% to 4.82% in men and from 0.25% to 7.06% in women.

CONCLUSIONS/INTERPRETATION

The results support the hypothesis that an increase in BMI in earlier adulthood is more strongly associated with unfavourable circulating levels of obesity biomarkers later in life than is an increase in BMI in later adulthood.

Psychosocial interventions for smoking cessation in patients with coronary heart disease

BACKGROUND

Quitting smoking improves prognosis after a cardiac event, but many patients continue to smoke, and improved cessation aids are urgently required.

OBJECTIVES

To assess the effectiveness of psychosocial interventions such as behavioural therapeutic intervention, telephone support and self-help interventions in helping people with coronary heart disease (CHD) to quit smoking.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (issue 2 2003), MEDLINE, EMBASE, PsycINFO and PSYNDEX were searched from the start of the database to August 2003. Results were supplemented by cross-checking references, and handsearches in selected journals and systematic reviews.

SELECTION CRITERIA

Randomised controlled studies (RCTs) in patients with CHD with a minimum follow-up of 6 months. After initial selection of the studies three trials with methodological flaws (e.g. high drop out) were excluded.

DATA COLLECTION AND ANALYSIS

Abstinence rates were computed according to an intention to treat analysis if possible, or if not on follow-up results only.

MAIN RESULTS

We found 16 RCTs meeting inclusion criteria. Interventions consist of behavioural therapeutic approaches, telephone support and self-help material and were either focused on smoking cessation alone or addressed several risk factors. The trials mostly included older male patients with CHD, predominantly myocardial infarction. Overall there was a positive effect of interventions on abstinence after 6 to 12 months (odds ratio (OR) 1.66, 95% confidence interval (CI) 1.25 to 2.22), but substantial heterogeneity between trials. Studies with validated assessment of smoking status at follow-up had lower efficacy (OR 1.44, 95% CI 0.99 to 2.11) than non-validated trials (OR 1.92, 95% CI 1.26 to 2.93). Studies were clustered by intervention strategy and intensity of the intervention. Clustering reduced heterogeneity, although many trials used more than one type of intervention. The ORs for different strategies were similar (behavioural therapies OR 1.69, 95% CI 1.33 to 2.14; telephone support OR 1.58, 95% CI 1.28 to 1.97; self-help OR 1.48, 95% CI 1.11 to 1.96). More intense interventions showed increased quit rates (OR 1.98, 95% CI 1.49 to 2.65) whereas brief interventions did not appear effective (OR 0.92, 95% CI 0.70 to 1.22). Two trials had longer term follow-up, and did not show any benefits after 5 years.

AUTHORS' CONCLUSIONS

Psychosocial smoking cessation interventions are effective in promoting abstinence at 1 year, provided they are of sufficient duration. Further studies, with longer follow-up, should compare different psychosocial intervention strategies, or the addition of a psychosocial intervention strategy to pharmacological therapy (e.g. nicotine replacement therapy) compared with pharmacological treatment alone.

Weight change and mortality: the Nord-Trøndelag Health Study

OBJECTIVES

The prevalence of obesity is increasing. Overweight and obese people have increased mortality compared with normal weight people. We investigated the effect of weight change on mortality.

DESIGN

Prospective population study.

SETTING

We utilized data from two large population-based health studies conducted in 1984-86 and 1995-97 respectively. Cox proportional hazards models were used to calculate mortality rate ratios (RRs) with 95% confidence intervals (CIs) between people with a stable weight and people who lost or gained weight. Subjects. Totally 20,542 men and 23,712 women aged 20 years or more, without cardiovascular disease or diabetes at the first survey and without a history of cancer at the second survey were followed up on all-cause mortality for 5 years after the second survey.

RESULTS

We found no association between weight gain and mortality. People who lost weight had a higher total mortality rate compared with those who were weight stable [RR was 1.6 (95% CI: 1.4-1.8) in men and 1.7 (95% CI: 1.5-2.0) in women]. Similar associations were found for cardiovascular and noncardiovascular mortality. Additional analysis showed a linear increase in mortality rates across categories of weight loss for both men and women (P < 0.001). There was a statistically significant interaction between weight change and initial BMI, but only amongst men (P = 0.001).

CONCLUSIONS

Weight loss, but not weight gain, was associated with increased mortality amongst men and women. Although underlying undiagnosed disease is the most plausible explanation for this finding, the similar associations found for total mortality, cardiovascular mortality, and noncardiovascular mortality makes the causal pathway somewhat enigmatic.

Physical consequences of schizophrenia and its treatment: the metabolic syndrome

Schizophrenia is a life shortening illness. Unnatural causes and natural causes are put forward as reasons for this excess mortality. In terms of the latter, a host of different physical disorders occur with increased frequency in schizophrenia. When taken together, some of these illnesses such as type 2 diabetes mellitus and cardiovascular disorders constitute the Metabolic Syndrome; a characteristic phenotype of those with this syndrome is excessive visceral fat distribution. The exact reasons why this particular syndrome occurs in schizophrenia is as yet unclear though factors such as life style, poor diet and lack of exercise may contribute to it's development. Alternatively, overactivity of the hypothalamic-pituitary-adrenal axis leading to hypercortisolaemia can also result in excessive visceral fat accumulation. This minireview aims to explore the potential role of these issues and medication in terms of the increased morbidity and mortality observed in schizophrenia.

Bodyweight gain associated with atypical antipsychotics: epidemiology and therapeutic implications

Atypical antipsychotic medications are associated with different adverse effects and efficacy profiles compared with conventional antipsychotics (i.e. less extrapyramidal symptoms, improved-efficacy against negative symptoms and cognitive deficits, and most often a greater ability to improve patients' quality of life). However, the atypical antipsychotics may be associated with clinically significant bodyweight gain, increasing the risk of medical comorbidity, including diabetes mellitus, hypertension, cardiovascular disease and hyperlipidaemia. This literature review assesses the various bodyweight gain liabilities associated with atypical antipsychotics, as well as the effects of bodyweight gain on quality of life. The issue of prevention and management of this often neglected adverse effect is also examined. Most studies reviewed indicate that clozapine and olanzapine are associated with more bodyweight gain than the other atypical antipsychotics. There are potential factors that place certain patients at greater risk for bodyweight gain, including low pretreatment body mass index, young age and being of female gender. Furthermore, bodyweight gain associated with the use of atypical antipsychotics has been reported to be associated with clinical improvement, although this has not been substantiated widely. It is unclear whether increased medical comorbidity, including diabetes mellitus, coronary artery disease and/or elevated triglyceride levels, is secondary to the bodyweight gain associated with atypical antipsychotics, or the result of the agents themselves. A patient's quality of life may be greatly affected by excessive bodyweight gain; either by increased comorbid medical illness, an increased relapse rate associated with noncompliance, or the social stigma associated with being obese. However, most studies reveal that treatment with atypical antipsychotic medications is associated with improved quality of life compared with that achieved with conventional antipsychotic medications. Because bodyweight is an important health risk associated with atypical antipsychotics, prevention and effective management of bodyweight are paramount in preventing comorbid medical illness, relapse and possible noncompliance.

Obesity and disease management: effects of weight loss on comorbid conditions

OBJECTIVE

This review is designed to quantitate the effects of obesity and weight gain on risk for coronary heart disease (CHD) and to review the effects of weight loss on CHD risk factors.

RESEARCH METHODS AND PROCEDURES

After a comprehensive review of the literature related to body weight and weight gain on CHD risk, the relative risks (RRs) were tabulated. Values were averaged and meta-analysis techniques were used to estimate the variance-adjusted RR.

RESULTS

Young persons with higher body mass index values have a significantly higher risk for CHD than do slender young people. For every 1% above a desirable body mass index, the risk for CHD increases by 3.3% for women and by 3.6% for men. Every kilogram of weight gain after high school increases risk for CHD by 5.7% for women and 3.1% for men. Weight loss significantly decreases major CHD risk factors. For every kilogram of weight loss the following favorable changes occur: fasting serum cholesterol, -1.0%; low-density lipoprotein cholesterol, -0.7%; triglycerides, -1.9%; high-density lipoprotein cholesterol, +0.2%; systolic blood pressure, -0.5%; diastolic blood pressure, -0.4%; and blood glucose, -0.2 mM.

DISCUSSION

Obesity and/or weight gain are associated with major risk for CHD. Weight loss significantly improves serum lipid parameters, blood pressure, and fasting blood glucose values. Effective treatment approaches are available for most overweight or obese individuals but a major challenge is to enable these individuals to engage in these programs. Professional and consumer education is essential for advancing effective intervention strategies for overweight individuals.

Cholesterol: an important but relatively overemphasized risk factor for ischemic heart disease

Educational messages directed at the public to prevent ischemic heart disease (IHD) are generally based on cholesterol-reduction. However, IHD has multiple risk factors, and a study was performed to help determine whether or not the allocation of educational messages among risk factors is appropriate: The severity of high cholesterol was compared with the severity of multiple other major risk factors for IHD, and the beneficial effects of cholesterol-reduction was compared with the benefits of multiple other major preventative factors for IHD. It was found that high cholesterol levels, and multiple other risk factors, generally give a risk of around 2.0 for developing IHD. Cholesterol-reduction by statins, and multiple other factors which prevent IHD, generally reduce the risk of IHD by about 30-40%. It was concluded that the allocation of educational messages to reduce the incidence of IHD should significantly increase discussions of non-cholesterol risk and preventative factors.

Prevention of coronary heart disease. Part I. Primary prevention

The first concern in primary prevention is the physician's belief that primary prevention is important for all adults and that intervention can significantly affect risk. Given the coronary plaque burden over many years and the importance of the development of healthy lifestyles early in adulthood to decrease coronary plaque burden, there are excellent reasons to begin prevention even with young adults. At the very least, a patient seen for any reason should provide a smoking history, have knowledge of the presence of early CHD in first-degree relatives and measurements of blood pressure, height, and weight, provide evidence for a cholesterol level within 5 years (after age 20 according to NCEP guidelines or in middle age according to ACP guidelines), and be given an assessment of glucose tolerance or diabetes. Information about alcohol intake and physical activity status are also of some importance. Other than height, weight, and blood pressure, during the physical examination, the physician should initially assess the strength of pulses in the lower extremities, evidence for carotid or femoral bruits, and eyegrounds for retinal arterial changes, and the skin and subcutaneous tissue should be examined for xanthomas and the eyes should be examined for corneal arcus and xanthelesma. These elements should be part of any initial examination by a primary care physician and are not extraordinary. In addition to lipid and blood sugar analyses, other evaluations may include blood urea nitrogen and creatinine and electrolytes in patients with hypertension or diabetes or in patients who are on antihypertensive agents. It may be prudent to obtain an ECG for patients who are older than 40 years. The elements mentioned above are the elements of the history, physical examination, and laboratory examination in subjects without a past history of CHD and with no clinical evidence for CHD. Primary prevention management begins with a discussion of risk factors with the patient. The key interventions aim at the lowering of blood pressure to at least less than 140/90 mm Hg, the complete cessation of smoking, the lowering of lipid levels to less than 130 mg/dL, the lowering of triglycerides to less than 200 mg/dL (or, some would argue, < 150 mg/dL), and the attempt to keep HDL cholesterol above 35 mg/dL (more than 40 to 45 mg/dL is a better goal) with the use of lifestyle modification. For patients with diabetes, strict control of glucose levels is essential to minimize disease of the microvasculature and possibly to minimize progressive renal disease. There are several lifestyle modifications for lipids. For patients with elevated LDL cholesterol, modifications include a less than 30% fat calorie diet and less than 300 mg of cholesterol intake daily, with fat calories approximately equally distributed among saturated fats, polyunsaturated fats, and monounsaturated fats (1/3, 1/3, 1/3; rule of 3s). The assistance of a dietician is extremely helpful in this regard. For patients with a low HDL cholesterol, weight reduction (for overweight patients) by calorie control and increased physical activity and smoking cessation will have some modest effect. For patients with elevated triglycerides, a diet similar to that for lowering of LDL cholesterol with the addition of stricter calorie limitation, avoidance of refined sugars, increase in complex carbohydrates, and avoidance of alcohol will be helpful. A decrease in the percent of fat calories to 20% to 25% will be of assistance to those patients with particularly high triglycerides. The treatment of underlying conditions such as diabetes mellitus, hypothyroidism, liver disease, and some renal conditions may also significantly modify high triglycerides. For patients with hypertension, limitation of sodium to 2 gm/d (6 gm sodium chloride), limitation of alcohol to 1 to 2 drinks a day, increased physical activity, and weight reduction are the key lifestyle modifications. (ABSTRACT TRUNCATED)

Antipsychotic-induced weight gain: a comprehensive research synthesis

OBJECTIVE

The purpose of this study was to estimate and compare the effects of antipsychotics-both the newer ones and the conventional ones-on body weight.

METHOD

A comprehensive literature search identified 81 English- and non-English-language articles that included data on weight change in antipsychotic-treated patients. For each agent, a meta-analysis and random effects metaregression estimated the weight change after 10 weeks of treatment at a standard dose. A comprehensive narrative review was also conducted on all articles that did not yield quantitative information but did yield important qualitative information.

RESULTS

Placebo was associated with a mean weight reduction of 0.74 kg. Among conventional agents, mean weight change ranged from a reduction of 0.39 kg with molindone to an increase of 3.19 kg with thioridazine. Among newer antipsychotic agents, mean increases were as follows: clozapine, 4.45 kg; olanzapine, 4.15 kg; sertindole, 2.92 kg; risperidone, 2.10 kg; and ziprasidone, 0.04 kg. Insufficient data were available to evaluate quetiapine at 10 weeks.

CONCLUSIONS

Both conventional and newer antipsychotics are associated with weight gain. Among the newer agents, clozapine appears to have the greatest potential to induce weight gain, and ziprasidone the least. The differences among newer agents may affect compliance with medication and health risk.