Il Suh

Smoking cessation and risk of type 2 diabetes mellitus: Korea Medical Insurance Corporation Study

Background To investigate the independent effects of smoking cessation on the risk for developing type 2 diabetes mellitus (DM) in the general population. Design An 8-year prospective study. Methods This prospective study started with baseline examinations in 1990 and 1992, and continued with follow-up examinations every 2 years up to 1998 and 2000. A total of 27635 nondiabetic men, aged 35–44 years were classified as 5701 nonsmokers, 7477 ex-smokers and 14457 sustained smokers, based on repeated self-reported questionnaires in 1992, 1994 and 1996. Baseline fasting serum glucose level and other risk factors were measured in 1990 and 1992. The outcome was newly developed DM, defined as a fasting glucose level ≥7.0mmol/l in 1998 and 2000 (averaged). Results Over the 8 years, 1170 men (4.2%) developed DM. When compared with nonsmokers, the fully adjusted risk ratio of ex-smokers and sustained smokers for diabetes was 1.22 [95% confidence interval (CI), 0.96–1.55] and 1.60 (95% CI, 1.29–1.97), respectively. Among the ex-smokers, the risk for diabetes differed according to the quit-smoking period. Compared with nonsmokers, the fully adjusted risk ratio for DM in men who quit smoking before 1992, during 1992–1993 and during 1994–1995 was 0.95 (0.72–1.25), 1.44 (0.96–2.15) and 2.13 (1.51–3.00), respectively, after adjustment for age, baseline fasting serum glucose, weight change, baseline body mass index, family history of DM, alcohol consumption and exercise status. Conclusions Our results support cigarette smoking as an independent and modifiable risk factor for DM. Early smoking cessation could decrease the risk for developing DM to that of nonsmokers in the long term.

VARIANCE IMPUTATION FOR OVERVIEWS OF CLINICAL TRIALS WITH CONTINUOUS RESPONSE

Overviews of clinical trials are an efficient and important means of summarizing information about a particular scientific area. When the outcome is a continuous variable, both treatment effect and variance estimates are required to construct a confidence interval for the overall treatment effect. Often, only partial information about the variance is provided in the publication of the clinical trial. This paper provides heuristic suggestions for variance imputation based on partial variance information. Both pretest-posttest (parallel groups) and crossover designs are considered. A key idea is to use separate sources of incomplete information to help choose a better variance estimate. The imputation suggestions are illustrated with a data set.

Alcohol Use and Mortality from Coronary Heart Disease: The Role of High-Density Lipoprotein Cholesterol

Abstract ▪Objective:To study the association between alcohol consumption and death from coronary heart disease and to determine the extent to which the association can be explained by the high-dens...

The Effect of Chronic Coffee Drinking on Blood Pressure: A Meta-Analysis of Controlled Clinical Trials

We sought to assess the effect of coffee consumption on blood pressure in humans. Our data sources included a MEDLINE search of the literature published before December 1997, bibliography review, and expert consultation. We selected controlled trials in which coffee consumption was the only difference between the intervention and control groups, mean blood pressure change was reported for each group or period, and treatment lasted for >24 hours. Of 36 studies initially identified, 11 (522 participants) met these inclusion criteria. Information on sample size, study design, participant characteristics (gender, race, age, baseline blood pressure, and antihypertensive medications), and treatment results were abstracted by 3 reviewers using a standardized protocol. Treatment effect of coffee consumption on blood pressure was estimated with the use of a random-effects model. In the 11 trials, median duration was 56 days (range, 14 to 79 days), and median dose of coffee was 5 cups/d. Systolic and diastolic blood pressure increased by 2.4 (range, 1.0 to 3.7) mm Hg and 1.2 (range, 0.4 to 2.1) mm Hg, respectively, with coffee treatment compared with control. Multiple linear regression analysis identified an independent, positive relationship between cups of coffee consumed and subsequent change in systolic blood pressure, independent of age of study participants and study design characteristics. The effect of coffee drinking on systolic and diastolic blood pressure was greater in trials with younger participants. Our findings provide support for a relationship between coffee consumption and higher blood pressure. Trials of coffee cessation of longer duration and in persons with hypertension should be performed.

Optimal Duration of Dual Antiplatelet Therapy after Drug-Eluting Stent Implantation: A Randomized Controlled Trial

Background— The risks and benefits of long-term dual antiplatelet therapy remain unclear. Methods and Results— This prospective, multicenter, open-label, randomized comparison trial was conducted in 24 clinical centers in Korea. In total, 5045 patients who received drug-eluting stents and were free of major adverse cardiovascular events and major bleeding for at least 12 months after stent placement were enrolled between July 2007 and July 2011. Patients were randomized to receive aspirin alone (n=2514) or clopidogrel plus aspirin (n=2531). The primary end point was a composite of death resulting from cardiac causes, myocardial infarction, or stroke 24 months after randomization. At 24 months, the primary end point occurred in 57 aspirin-alone group patients (2.4%) and 61 dual-therapy group patients (2.6%; hazard ratio, 0.94; 95% confidence interval, 0.66–1.35; P=0.75). The 2 groups did not differ significantly in terms of the individual risks of death resulting from any cause, myocardial infarction, stent thrombosis, or stroke. Major bleeding occurred in 24 (1.1%) and 34 (1.4%) of the aspirin-alone group and dual-therapy group patients, respectively (hazard ratio, 0.71; 95% confidence interval, 0.42–1.20; P=0.20). Conclusions— Among patients who were on 12-month dual antiplatelet therapy without complications, an additional 24 months of dual antiplatelet therapy versus aspirin alone did not reduce the risk of the composite end point of death from cardiac causes, myocardial infarction, or stroke. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01186146.

Hypertension: its prevalence and population-attributable fraction for mortality from cardiovascular disease in the Asia-Pacific region.

Objective About half of the worlds burden of cardiovascular disease is carried by countries in the Asia-Pacific region. This study aimed to quantify the contribution of hypertension to cardiovascular diseases (CVD) at the country level, by calculating the sex-specific, population-attributable fractions (PAFs) for fatal ischaemic heart disease (IHD) and stroke (haemorrhagic and ischaemic) for the World Health Organization Western Pacific and South-east Asian regions. Methods The most recent sex-specific prevalence data on hypertension were sought. Age-adjusted hazard ratio (HR) estimates for fatal IHD and stroke associated with hypertension were obtained using Cox analyses of individual participant cohort data from 600 000 adult participants in the Asia-Pacific Cohort Studies Collaboration. HR estimates and prevalence were then used to calculate sex-specific PAFs for fatal IHD and stroke, by country. Results In 15 countries with available data, the prevalence of hypertension ranged from 5–47% in men and from 7–38% in women. Overall, the fraction of IHD attributable to hypertension ranged from 4–28% in men and from 8–39% in women. Corresponding ranges for haemorrhagic stroke were 18–66% and 15–49%, and for ischaemic stroke were 8–44% and 12–45%. Conclusions In the Asia-Pacific region, up to 66% of some subtypes of CVD can be attributed to hypertension, underscoring the immense impact that blood pressure- lowering strategies could have in this populous region.

Country actions to meet UN commitments on non-communicable diseases: a stepwise approach

Strong leadership from heads of state is needed to meet national commitments to the UN political declaration on non-communicable diseases (NCDs) and to achieve the goal of a 25% reduction in premature NCD mortality by 2025 (the 25 by 25 goal). A simple, phased, national response to the political declaration is suggested, with three key steps: planning, implementation, and accountability. Planning entails mobilisation of a multisectoral response to develop and support the national action plan, and to build human, financial, and regulatory capacity for change. Implementation of a few priority and feasible cost-effective interventions for the prevention and treatment of NCDs will achieve the 25 by 25 goal and will need only few additional financial resources. Accountability incorporates three dimensions: monitoring of progress, reviewing of progress, and appropriate responses to accelerate progress. A national NCD commission or equivalent, which is independent of government, is needed to ensure that all relevant stakeholders are held accountable for the UN commitments to NCDs.

Low serum cholesterol and haemorrhagic stroke in men: Korea Medical Insurance Corporation Study

BACKGROUND In some prospective studies, haemorrhagic stroke occurs more frequently in individuals with low serum cholesterol than in those with higher concentrations. We aimed to determine whether low total serum cholesterol is an independent risk factor for haemorrhagic stroke (intracerebral haemorrhage and subarachnoid haemorrhage) in South Korea, a country that has a population with relatively low concentrations of total serum cholesterol. METHODS We measured total serum cholesterol and other cardiovascular risk factors in 114,793 Korean men, aged between 35-59 years in 1990 and 1992, in a prospective observational study. We used data obtained in 1992 for smoking and alcohol consumption. We divided total serum cholesterol into quintiles (<4.31 mmol/L, 4.31-<4.74, 4.74-<5.16, 5.16-<5.69 and > or = 5.69). Our primary outcomes were hospital admissions and deaths from intracerebral and subarachnoid haemorrhage in a 6 year follow-up between 1993 and 1998. FINDINGS 528 men had a haemorrhagic stroke--372 intracerebral and 98 subarachnoid haemorrhage--and 58 were unspecified strokes. The relative risks of intracerebral haemorrhage in each quintile of total serum cholesterol (lowest to highest were: 1.22 (95% CI 0.88-1.69); 0.86 (0.60-1.21); 1.08 (0.78-1.48); and 1.03 (0.75-1.41). The corresponding relative risks for subarachnoid haemorrhage were: 1.44 (0.76-2.73); 1.13 (0.59-2.20); 1.21 (0.64-2.29); and 1.12 (0.59-2.14). INTERPRETATION Low total serum cholesterol is not an independent risk factor for either intracerebral or subarachnoid haemorrhagic stroke in Korean men.

Smoking and elevated blood pressure are the most important risk factors for subarachnoid hemorrhage in the Asia-Pacific Region: an overview of 26 cohorts involving 306,620 participants

Background and Purpose— The cause of subarachnoid hemorrhage (SAH) is poorly understood and there are few large cohort studies of risk factors for SAH. We investigated the risk of SAH mortality and morbidity associated with common cardiovascular risk factors in the Asia-Pacific region and examined whether the strengths of these associations were different in Asian and Australasian (predominantly white) populations. Methods— Cohort studies were identified from Internet electronic databases, searches of proceedings of meetings, and personal communication. Hazard ratios (HRs) for systolic blood pressure (SBP), current smoking, total serum cholesterol, body mass index (BMI), and alcohol drinking were calculated from Cox models that were stratified by sex and cohort and adjusted for age at risk. Results— Individual participant data from 26 prospective cohort studies (total number of participants 306 620) that reported incident cases of SAH (fatal and/or nonfatal) were available for analysis. During the median follow-up period of 8.2 years, a total of 236 incident cases of SAH were observed. Current smoking (HR, 2.4; 95% CI, 1.8 to 3.4) and SBP >140 mm Hg (HR, 2.0; 95% CI, 1.5 to 2.7) were significant and independent risk factors for SAH. Attributable risks of SAH associated with current smoking and elevated SBP (≥140 mm Hg) were 29% and 19%, respectively. There were no significant associations between the risk of SAH and cholesterol, BMI, or drinking alcohol. The strength of the associations of the common cardiovascular risk factors with the risk of SAH did not differ much between Asian and Australasian regions. Conclusions— Cigarette smoking and SBP are the most important risk factors for SAH in the Asia-Pacific region.

Cigarette Smoking, Systolic Blood Pressure, and Cardiovascular Diseases in the Asia-Pacific Region

Background and Purpose— Smoking and increased levels of blood pressure (BP) substantially increase the risk of cardiovascular diseases (CVD). If these 2 risk factors have a synergistic impact on cardiovascular events, lowering BP and quitting smoking will contribute more to reducing CVD than would be expected from ignoring their interaction. Methods— Individual participant data were combined from 41 cohorts, involving 563 144 participants (82% Asian). During a median of 6.8 years follow-up, 4344 coronary heart disease (CHD) and 5906 stroke events were recorded. Repeat measures of systolic blood pressure (SBP) were used to adjust for regression dilution bias. Hazard ratios (HRs) and 95% confidence intervals (CIs) for SBP by cigarette smoking status were estimated from Cox proportional hazard models adjusted for age and stratified by study and sex. Results— Data suggested a log-linear relationship between SBP and all subtypes of CVD. The HRs relating SBP to both CHD and ischemic stroke were broadly similar irrespective of smoking status (P≥0.1). For hemorrhagic stroke (intracerebral hemorrhage), the HRs (95% CIs) for an additional 10 mm Hg increment in SBP were 1.81 (1.73 to 1.90) for present smokers and 1.66 (1.59 to 1.73) for nonsmokers (P=0.003). For every subtype of cardiovascular events, similar results were found for analyses involving only fatal events. Conclusions— Smoking exacerbated the impact of SBP on the risk of hemorrhagic stroke. Although quitting smoking and lowering BP are both crucial for prevention of CVD, combining the 2 could be expected to have extra beneficial effect on preventing hemorrhagic stroke.