Does risk factor epidemiology put epidemiology at risk? Peering into the future.
The multiple cause black box paradigm of the current risk factor era in epidemiology is growing less serviceable. This single level paradigm is likely to be displaced. The signs are that the growing strength of molecular epidemiology on the one side, and of a global epidemiology based on information systems on the other, will come to dominate epidemiology and segregate it into separate disciplines. At the same time, the links with public health interests grow weaker. A multilevel ecoepidemiology has the potential to bind these strands together. (+info
Comparative total mortality in 25 years in Italian and Greek middle aged rural men.
STUDY OBJECTIVE: Mortality over 25 years has been low in the Italian and very low in the Greek cohorts of the Seven Countries Study; factors responsible for this particularity were studied in detail. PARTICIPANTS AND SETTINGS: 1712 Italian and 1215 Greek men, aged 40-59 years, cohorts of the Seven Countries Study, representing over 95% of the populations in designated rural areas. DESIGN: Entry (1960-61) data included age, systolic blood pressure (SBP), smoking habits, total serum cholesterol, body mass index (BMI), arm circumference, vital capacity (VC), and forced expiratory volume in 3/4 seconds (FEV); the same data were obtained 10 years later. Multivariate Cox analysis was performed with all causes death in 25 years as end point. MAIN RESULTS: Italian men had higher entry levels of SBP, arm circumference, BMI, and VC; Greek men had higher cholesterol levels, smoking habits, and FEV. Mortality of Italian men was higher throughout; at 25 years cumulative mortality was 48.3% and 35.3% respectively. Coronary heart disease and stroke mortality increased fivefold in Italy and 10-fold in Greece between years 10 and 25. The only risk factor with a significantly higher contribution to mortality in Italian men was cholesterol. However, differences in entry SBP (higher in Italy) and FEV (higher in Greece) accounted for, according to the Lee method, 75% of the differential mortality between the two populations. At 10 years increases in SBP, cholesterol, BMI, and decreases in smoking habits, VC, FEV, and arm circumference had occurred (deltas). SBP increased more and FEV and VC decreased more in Italy than in Greece. Deltas, fed stepwise in the original model for the prediction of 10 to 25 years mortality, were significant for SBP, smoking, arm circumference, and VC in Greece, and for SBP and VC in Italy. CONCLUSION: Higher mortality in Italian men is related to stronger positive effects of entry SBP and weaker negative (protective) effects of FEV; in addition 10 year increases in SBP are higher and 10 year decreases in FEV are larger in Italy. Unaccounted factors, however, related to, for example, differences in the diet, may also have contributed to the differential mortality of these two Mediterranean populations. (+info
Physician advice and individual behaviors about cardiovascular disease risk reduction--seven states and Puerto Rico, 1997.
Cardiovascular disease (CVD) (e.g., heart disease and stroke) is the leading cause of death in the United States and accounted for 959,227 deaths in 1996. Strategies to reduce the risk for heart disease and stroke include lifestyle changes (e.g., eating fewer high-fat and high-cholesterol foods) and increasing physical activity. The U.S. Preventive Services Task Force and the American Heart Association (AHA) recommend that, as part of a preventive health examination, all primary-care providers counsel their patients about a healthy diet and regular physical activity. AHA also recommends low-dose aspirin use as a secondary preventive measure among persons with existing CVD. To determine the prevalence of physician counseling about cardiovascular health and changes in individual behaviors, CDC analyzed data from the Behavioral Risk Factor Surveillance System (BRFSS) for seven states and Puerto Rico. This report summarizes the results of that analysis, which indicate a lower prevalence of counseling and behavior change among persons without than with a history of heart disease or stroke. (+info
Risk of major liver resection in patients with underlying chronic liver disease: a reappraisal.
OBJECTIVE: To explore the relation of patient age, status of liver parenchyma, presence of markers of active hepatitis, and blood loss to subsequent death and complications in patients undergoing a similar major hepatectomy for the same disease using a standardized technique. SUMMARY BACKGROUND DATA: Major liver resection carries a high risk of postoperative liver failure in patients with chronic liver disease. However, this underlying liver disease may comprise a wide range of pathologic changes that have, in the past, not been well defined. METHODS: The nontumorous liver of 55 patients undergoing a right hepatectomy for hepatocellular carcinoma was classified according to a semiquantitative grading of fibrosis. The authors analyzed the influence of this pathologic feature and of other preoperative variables on the risk of postoperative death and complications. RESULTS: Serum bilirubin and prothrombin time increased on postoperative day 1, and their speed of recovery was influenced by the severity of fibrosis. Incidence of death from liver failure was 32% in patients with grade 4 fibrosis (cirrhosis) and 0% in patients with grade 0 to 3 fibrosis. The preoperative serum aspartate transaminase (ASAT) level ranged from 68 to 207 IU/l in patients with cirrhosis who died, compared with 20 to 62 in patients with cirrhosis who survived. CONCLUSION: A major liver resection such as a right hepatectomy may be safely performed in patients with underlying liver disease, provided no additional risk factors are present. Patients with a preoperative increase in ASAT should undergo a liver biopsy to rule out the presence of grade 4 fibrosis, which should contraindicate this resection. (+info
Use of wood stoves and risk of cancers of the upper aero-digestive tract: a case-control study.
BACKGROUND: Incidence rates for cancers of the upper aero-digestive tract in Southern Brazil are among the highest in the world. A case-control study was designed to identify the main risk factors for carcinomas of mouth, pharynx, and larynx in the region. We tested the hypothesis of whether use of wood stoves is associated with these cancers. METHODS: Information on known and potential risk factors was obtained from interviews with 784 cases and 1568 non-cancer controls. We estimated the effect of use of wood stove by conditional logistic regression, with adjustment for smoking, alcohol consumption and for other sociodemographic and dietary variables chosen as empirical confounders based on a change-in-estimate criterion. RESULTS: After extensive adjustment for all the empirical confounders the odds ratio (OR) for all upper aero-digestive tract cancers was 2.68 (95% confidence interval [CI] : 2.2-3.3). Increased risks were also seen in site-specific analyses for mouth (OR = 2.73; 95% CI: 1.8-4.2), pharyngeal (OR = 3.82; 95% CI: 2.0-7.4), and laryngeal carcinomas (OR = 2.34; 95% CI: 1.2-4.7). Significant risk elevations remained for each of the three anatomic sites and for all sites combined even after we purposefully biased the analyses towards the null hypothesis by adjusting the effect of wood stove use only for positive empirical confounders. CONCLUSIONS: The association of use of wood stoves with cancers of the upper aero-digestive tract is genuine and unlikely to result from insufficient control of confounding. Due to its high prevalence, use of wood stoves may be linked to as many as 30% of all cancers occurring in the region. (+info
Helicobacter pylori infection, garlic intake and precancerous lesions in a Chinese population at low risk of gastric cancer.
BACKGROUND: Cangshan County of Shandong Province has one of the lowest rates of gastric cancer (GC) in China. While intestinal metaplasia (IM) and dysplasia (DYS) are less common in Cangshan than in areas of Shandong at high risk of GC, these precursor lesions nevertheless affect about 20% of adults age > or = 55. SUBJECTS AND SETTING: In order to evaluate determinants of IM and DYS in Cangshan County, a low risk area of GC a survey was conducted among 214 adults who participated in a gastroscopic screening survey in Cangshan County in 1994. METHOD: A dietary interview and measurement of serum Helicobacter pylori antibodies were performed. RESULTS: The prevalence of H. pylori was lowest (19%) among those with normal gastric mucosa, rising steadily to 35% for superficial gastritis (SG), 56% for chronic atrophic gastritis (CAG), 80% for IM, and 100% for DYS. The prevalence odds of precancerous lesions were compared with the odds of normal histology or SG. The odds ratio (OR) or CAG associated with H. pylori positivity was 4.2 (95% confidence interval [CI] : 1.7-10.0), while the OR of IM/DYS associated with H. pylori positivity was 31.5 (95% CI: 5.2-187). After adjusting for H. pylori infection, drinking alcohol was a risk factor for CAG (OR = 3.2, 95% CI: 1.1-9.2) and IM/DYS (OR = 7.8, 95% CI: 1.3-47.7). On the other hand, consumption of garlic showed non-significant protective effects and an inverse association with H. pylori infection. CONCLUSIONS: The findings of this study suggest that infection with H. pylori is a risk factor and garlic may be protective, in the development and progression of advanced precancerous gastric lesions in an area of China at relatively low risk of GC. (+info
Precancerous lesions in two counties of China with contrasting gastric cancer risk.
BACKGROUND: Gastric cancer (GC) is one of the most common cancers worldwide and shows remarkable geographical variation even within countries such as China. Linqu County in Shandong Province of northeast China has a GC rate that is 15 times higher than that of Cangshan County in Shandong, even though these counties are within 200 miles of each other. METHOD: In order to evaluate the frequency of precancerous gastric lesions in Linqu and Cangshan Counties we examined 3400 adults in Linqu County and 224 adults in Cangshan County. An endoscopic examination with four biopsies was performed in each individual of the two populations. RESULTS: The prevalence of intestinal metaplasia (IM) and dysplasia (DYS) was 30% and 15.1%, respectively, in Linqu compared to 7.9% and 5.6% in Cangshan (P < 0.01). Within these histological categories, advanced grades were found more often in Linqu than in Cangshan. The prevalences of IM and DYS were more common at each biopsy site in Linqu, where the lesions also tended to affect multiple sites. CONCLUSIONS: The findings of this study support the concept that IM and DYS are closely correlated with risks of GC and represent late stages in the multistep process of gastric carcinogenesis. (+info
Serum triglyceride: a possible risk factor for ruptured abdominal aortic aneurysm.
BACKGROUND: We aimed to determine the relationship between ruptured abdominal aortic aneurysm (AAA) and serum concentrations of lipids and apolipoproteins. METHODS: A cohort of 21 520 men, aged 35-64 years, was recruited from men attending the British United Provident Association (BUPA) clinic in London for a routine medical examination in 1975-1982. Smoking habits, weight, height and blood pressure were recorded at entry. Lipids and apolipoproteins were measured in stored serum samples from the 30 men who subsequently died of ruptured AAA and 150 matched controls. RESULTS: Triglyceride was strongly related to risk of ruptured AAA. In univariate analyses the risk in men on the 90th centile of the distribution relative to the risk in men on the 10th (RO10-90) was 12 (95% confidence interval [CI] : 3.8-37) for triglyceride, 5.5 (95% CI: 1.8-17) for apolipoprotein B (apoB) (the protein component of low density lipoprotein [LDL]), 0.15 (95% CI : 0.04-0.56) for apo A1 (the protein component of high density lipoprotein [HDL]), 3.7 (95% CI: 1.4-9.4) for body mass index and 3.0 (95% CI: 1.1-8.5) for systolic blood pressure. Lipoprotein (a) (Lp(a)) was not a significant risk factor (RO10-90 = 1.6, 95% CI: 0.6-3.0). In multivariate analysis triglyceride retained its strong association. CONCLUSION: Triglyceride appears to be a strong risk factor for ruptured AAA, although further studies are required to clarify this. If this and other associations are cause and effect, then changing the distribution of risk factors in the population (by many people stopping smoking and adopting a lower saturated fat diet and by lowering blood pressure) could achieve an important reduction in mortality from ruptured AAA. (+info