Ethnic difference in the relationship between acute inflammation and serum ferritin in US adult males.

This study examined the ethnic difference in the association between increased serum ferritin (SF) (>300 microg/l) and acute inflammation (AI) (C-reactive protein > or = 1.0 mg/dl) between black and white males aged > or = 20 years. Using data from the third National Health and Nutrition Examination Survey (NHANES III), we determined the risk for having elevated SF in black males (n=164) and white males (n=325) with AI present as well as black males (n=1731) and white males (n=2877) with AI absent. Black subjects with AI present were 1.71 times (95% CI 1.18-2.49), and 1.87 times (95% CI 1.46-2.40) more likely to have increased SF than AI absent blacks and AI present whites, respectively. Furthermore, with AI present, every increment of C-reactive protein, white blood cell count, serum albumin, lymphocyte count and platelet count was associated with higher odds of having elevations in SF in blacks than whites. Regardless of AI status, blacks were more likely to have elevations in SF than whites, and the prevalence of elevated SF was significantly higher in blacks than whites. This finding suggested that black males may respond to inflammation with a more aggressive rise in SF compared to white males. Future research is needed to investigate the underlying mechanisms.

Comparison of BMI-for-age in adolescent girls in 3 countries of the Eastern Mediterranean Region.

International comparisons of adolescent overweight and obesity are hampered by the lack of a single agreed measurement reference. We compared 3 BMI-for-age references on samples of adolescent girls from Egypt, Kuwait and Lebanon. Overweight and obesity was highest in Kuwait and lowest in Lebanon. Performance of the 3 standards differed only slightly although one was particularly applicable in country-to-country comparisons.

Comparison of BMI-for-age in adolescent girls in 3 countries of the Eastern Mediterranean Region

International comparisons of adolescent overweight and obesity are hampered by the lack of a single agreed measurement reference. We compared 3 BMI- for- age references on samples of adolescent girls from Egypt, Kuwait and Lebanon. Overweight and obesity was highest in Kuwait and lowest in Lebanon. Performance of the 3 standards differed only slightly although one was particularly applicable in country- to- country comparisons

Helicobacter pylori, Chlamydia pneumoniae and myocardial infarction.

BACKGROUND: Several epidemiological studies have suggested a positive association of coronary heart disease with both Helicobacter pylori and Chlamydia pneumoniae infection. The issue has been difficult to resolve because of the potential impact of several confounding factors, in particular, socioeconomic status for H. pylori and smoking for C. pneumoniae. METHODS: A case-control study was carried out of 341 patients with a recent myocardial infarction (MI) and 831 community controls who had serology tests for H. pylori and C. pneumoniae (selected from a total study number of 1745 subjects). Individuals of Pacific Island or Maori ethnicity were excluded because they were infrequent. RESULTS: H. pylori seropositivity was associated with increasing age (P < 0.001) and lower household income (P = 0.0003) but not with gender, smoking status or alcohol intake. H. pylori was associated with lower high-density lipoprotein cholesterol (P = 0.007) and a higher body mass index (P = 0.007). The overall seropositivity for H. pylori was 41.6% for patients with MI and 34.5% for age and sex-matched population controls. The odds ratio was 1.34 (95% confidence interval (CI): 1.00-1.80; P = 0.038) after adjusting for age and sex. C. pneumoniae seropositivity was significantly associated with male sex, younger age (P = 0.03) and smoking status (P = 0.004) but not associated with household income or any other measured risk factor for coronary heart disease. The overall seropositivity for C. pneumoniae was 51.2% for patients with recent MI and 43.5% for controls. After adjusting for age and sex, the odds ratio was 1.24 (95%CI: 0.95-1.62; P = 0.11). Subgroup analysis showed no clear pattern within different age groups. In particular, the odds ratio for H. pylori seropositivity in younger subjects (aged 35-49 years) was similar to the overall group (1.38; 95%CI: 0.83-2.29). CONCLUSION: The association between H. pylori or C. pneumoniae seropositivity and coronary heart disease was significant but may not indicate a causal association.

Multiple coronary risk factors in healthy older Kuwaiti males.

OBJECTIVE: The objective was to examine the percentage and severity of obesity and some common biochemical coronary heart disease (CHD) risk factors in a sample of healthy Kuwaiti adult males > or =45 y of age. We also sought to determine the percentage of males at increased risk due to the presence of multiple CHD risk factors. DESIGN: The study was a cross-sectional study. SETTING: The study was conducted in all men who underwent a mandatory job related physical examination or who sought to obtain retirement benefits. SUBJECTS: A total of 740 healthy Kuwaiti males between the ages of 45 to 80 y. RESULTS: In all, 37% of the men were obese, 26% had elevated glucose values and 52% had elevated or high cholesterol levels. Some had multiple risk factors for CHD, including age > or =45 y, obesity, male gender, hyperglycemia and hypercholesterolemia. Blood glucose values increased consistently from younger (45-54 y) to older age groups (55-64 and > or =65 y). Blood glucose values varied inversely with education level. CONCLUSIONS: In societies with relatively uniform income levels, educational level may be a better indicator of chronic disease risk than income per se. These results, showing a high percentage of men with several risk factors and high mean values, suggesting more severe risk, suggest that immediate action should be taken to develop a public health intervention strategy to educate Kuwaiti men to become aware of the causes and correlates of CHD and how to decrease their risk for CHD and heart attack, the leading cause of death in Kuwait.

The New Zealand Blood Donors' Health Study: baseline findings of a large prospective cohort study of injury.

INTRODUCTION: Cohort studies have contributed important scientific knowledge regarding the determinants of chronic diseases. Despite the need for etiologic investigations, this design has been infrequently used in injury prevention research. OBJECTIVES: To describe the baseline findings of the New Zealand Blood Donors' Health Study, a large prospective study designed to investigate relationships between lifestyle, psychosocial factors, and serious injury due to road crashes, falls, self harm, assault, work, sport, and recreation. METHODS: Participants were recruited from fixed and mobile collection sites of a voluntary non-profit blood donor program. Baseline exposure data (for example risk taking behaviors, alcohol and marijuana use, sleep habits, and depression) were collected using a self administered questionnaire. Outcome data regarding serious injury will be collected prospectively through computerized record linkage of participants' unique identifiers to national morbidity and mortality databases. RESULTS: In total, 22 389 participants enrolled in the study (81% response rate). The diverse study population included 36% aged 16-24 years, 20% rural residents, and large variability in exposures of interest. For example, in the 12 months before recruitment, 21% had driven a motor vehicle when they considered themselves over the legal limit for alcohol, and 11% had been convicted of traffic violations (excluding parking infringements). Twelve per cent had seriously considered attempting suicide sometime in their life. CONCLUSIONS: This is the first, large scale cohort study investigating determinants of serious injury in New Zealand and among the largest worldwide. Preliminary findings from prospective analyses that can inform injury prevention policy are expected within five years.

Prevalence of coronary risk factors in healthy adult Kuwaitis.

Obesity has been shown to be a serious health risk and is associated with a wide range of comorbid conditions, including diabetes mellitus, coronary heart disease (CHD), gall bladder disease, hypertension, osteoarthritis, and certain cancers. Studies in Kuwait and other Gulf States indicate that obesity is prevalent and may be increasing. Previous studies in Kuwait have mostly focused on the epidemiology of overweight and obesity in children, adolescents, and young adults. Relatively less is known about the prevalence of overweight and obesity and its correlates in older adults for whom obesity may be more closely related to CHD risk. The purpose of this study was to examine the prevalence of overweight and obesity in 9755 adult men and women and to determine the relationship of weight to other risk factors for chronic disease. For the first time we examine a sample of older Kuwaitis to explore the relationship between high BMI, hypercholesterolemia and hyperglycemia. One-third of adult Kuwaitis are obese (BMI > 30 kg/m2), 4.7% of Kuwaiti females have severe obesity (BMI > 40 kg/m2). BMI, cholesterol, and glucose values increase with age across the life span. Older Kuwaitis have a greater constellation of risk factors for chronic diseases. The results of a multiple linear regression model in which cholesterol values were studied, controlling for age, BMI, blood glucose, and sex revealed that age, BMI and sex were significant predictors of cholesterol values. These results indicate that actions to reduce obesity, hypercholesterolemia, and hyperglycemia are needed.

Men who consume vegetable oils rich in monounsaturated fat: their dietary patterns and risk of prostate cancer (New Zealand).

OBJECTIVES: To investigate (i) dietary patterns associated with consumption of vegetable oils rich in monounsaturated fatty acids (MUFA), and (ii) the risk of prostate cancer associated with consumption of these oils. METHODS: A population-based case-control study was conducted in Auckland, New Zealand, involving 317 prostate cancer cases and 480 controls. A food-frequency questionnaire was used to collect data concerning consumption of MUFA-rich vegetable oils (including olive oil, canola or peanut oil) and other dietary variables. Biomarkers for fatty acids were measured in erythrocytes. RESULTS: The group of participants who reported regular consumption of greater than 5.5 ml of MUFA-rich vegetable oils per day had a diet relatively high in monounsaturated fat, vegetables, lycopene, vitamin E, selenium, and n-3 fish oils. Increasing levels of MUFA-rich vegetable oil intake were associated with a progressive reduction in prostate cancer risk (multivariate relative risk = 0.5; 95% confidence interval 0.3-0.9; > 5.5 ml per day vs. nonconsumption, p trend = 0.005), and similar trends were observed across all strata of socioeconomic status. Prostate cancer risk was not associated with intake of total MUFA or the major animal food sources of MUFA. CONCLUSION: This finding may be explained by the protective effect of an associated dietary pattern high in antioxidants and fish oils, an independent protective effect of MUFA-rich vegetable oils unrelated to the MUFA component, or a combination of these factors.

Iron deficiency is a more important cause of anemia than hemoglobinopathies in Kuwaiti adolescent girls.

Anemia is the most prevalent nutritional problem worldwide, due mainly to iron deficiency. Studies of anemia are less common in adolescents than in women and children. We examined anemia prevalence in adolescent Kuwaiti schoolgirls, and its association with hemoglobinopathies as well as the most common environmental cause, Fe deficiency. A cross-sectional sample of 1051 healthy adolescent schoolgirls was studied. Sample size was based on WHO criteria. Anemia, Fe deficiency and hemoglobin (Hb) variations were studied by Hb concentration, erythrocyte protoporphyrin (EP) and an HPLC quantitation, respectively. Of the subjects sampled, 30% were anemic. Mildly elevated EP values were found in 68%. Girls with high EP levels were more likely (P < 0.001) to be anemic than girls with normal EP. Up to 25% of the girls may have had Fe deficiency anemia. Hemoglobinopathies were neither prevalent nor significantly associated with anemia. These data indicate that environmental factors play a significant role in anemia among healthy, well-to-do Kuwaiti adolescent girls.

Height-related risk factors for prostate cancer.

Previous studies have reported that adult height is positively associated with the risk of prostate cancer. The authors carried out a population-based case-control study involving 317 prostate cancer cases and 480 controls to further investigate the possibility that height is more strongly associated with advanced, compared with localized forms of this disease. Since the inherited endocrine factors, which in part determine height attained during the growing years, may influence the risk of familial prostate cancer later in life, the relationship with height was also investigated for familial versus sporadic prostate cancers. Adult height was not related to the risk of localized prostate cancer, but there was a moderate positive association between increasing height and the risk of advanced cancer (relative risk (RR) = 1.62; 95% confidence interval (CI) 0.97-2.73, upper versus lowest quartile, P-trend = 0.07). Height was more strongly associated with the risk of prostate cancer in men with a positive family history compared with those reporting a negative family history. The RR of advanced prostate cancer for men in the upper height quartile with a positive family history was 7.41 (95% CI 1.68-32.67, P-trend = 0.02) compared with a reference group comprised of men in the shortest height quartile with a negative family history. Serum insulin-like growth factor-1 levels did not correlate with height amongst men with familial or sporadic prostate cancers. These findings provide evidence for the existence of growth-related risk factors for prostate cancer, particularly for advanced and familial forms of this disease. The possible existence of inherited mechanisms affecting both somatic and tumour growth deserves further investigation.

Prostate cancer and dietary carotenoids.

This population-based case-control study investigated associations between prostate cancer risk and dietary intake of the carotenoids beta-carotene and lycopene and their major plant food sources, including carrots, green leafy vegetables, and tomato-based foods. The study was carried out in Auckland, New Zealand, during 1996-1997 and recruited 317 prostate cancer cases and 480 controls. The authors found that dietary intake of beta-carotene and its main vegetable sources was largely unassociated with prostate cancer risk, whereas intake of lycopene and tomato-based foods was weakly associated with a reduced risk. These results suggest that in contrast to the findings regarding many types of cancers, vegetables rich in beta-carotene are not protective against prostate cancer. However, lycopene from tomato-based foods was found to be associated with a small reduction in risk.

A case-crossover analysis of a case-control study of alcohol consumption and coronary events: the effects of exposure definition and the use of control data.

BACKGROUND: Case-crossover studies can be used to assess the effects of transient exposures in acute events by comparing cases' exposures at the time of the event against their usual exposure. Cases from a case-control study can also be analysed by this method if appropriate information is obtained. METHODS: We apply the case-crossover method to data collected in a case-control study of acute coronary events, to estimate the risk of alcohol consumption in the 24 h before a coronary event. Two questions, concerning the usual frequency of consuming alcohol and how much was consumed, were used in the analysis. The sensitivity of effect estimates to the two questions and to different ways of eliciting probabilities from them, are examined. The cases and controls were both analysed in the same way, assigning controls a 'pseudo-event' time at random. It is suggested that controls may provide a benchmark to establish whether bias exists in the case-series analysis. RESULTS: We find that the case-crossover analysis is sensitive to how exposure probabilities are assigned. Adopting a Poisson model for exposures leads to inflated risk estimates. The bias is removed if the control series is used to adjust estimates. There appears to be a small protective effect from alcohol consumption. CONCLUSION: Case-crossover designs have considerable potential, but reliable information on usual exposure limits their applicability. More research is required on how best to elicit exposure probabilities.

Heterocyclic amine content of cooked meat and risk of prostate cancer.

BACKGROUND: Some epidemiologic studies have described positive associations between prostate cancer risk and meat consumption, but underlying mechanisms have not been identified. Heterocyclic amines are mutagens formed during the cooking of meat. Well-done meat has been associated with increased risks of colorectal and breast cancers in humans. This study examined associations between prostate cancer risk and 1) estimated daily intake of heterocyclic amines from cooked meat and 2) level of cooked-meat doneness. METHODS: A population-based, case-control study involving 317 case patients with prostate cancer and 480 age-matched control subjects was carried out in Auckland, New Zealand. Levels of meat doneness and daily intake of heterocyclic amines were determined from self-reported dietary data and experimentally measured heterocyclic amine levels in locally sourced meat samples cooked under controlled conditions to varying degrees of doneness. RESULTS: The heterocyclic amines found in the highest concentrations in meat samples were 2-amino-1,6-dimethylfuro[3,2-e]imidazo[4,5-b]pyridine (IFP) and 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) from well-done chicken and pork and very well-done beefsteak. Meat doneness was weakly and inconsistently associated with prostate cancer risk for individual types of meat, but increased risk was observed for well-done beefsteak (relative risk = 1.68; 95% confidence interval = 1.02-2.77; two-sided P for trend =.03). A weak positive gradient of increased risk was associated with estimated daily exposure to IFP but not with the other major heterocyclic amines. CONCLUSIONS: Meat doneness and estimated intake of heterocyclic amines from cooked meat were not clearly associated with prostate cancer risk.

Prostate cancer risk and consumption of fish oils: a dietary biomarker-based case-control study.

Experimental studies suggest that the risk of prostate cancer is reduced with the intake of long-chain n-3 polyunsaturated fatty acids derived from marine foods, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, few human studies have been conducted due to difficulties in assessing the dietary intake of these fatty acids. The authors examined the relationship between prostate cancer risk and EPA and DHA in erythrocyte biomarkers in a population-based case-control study in Auckland, New Zealand during 1996-1997 involving 317 prostate cancer cases and 480 age-matched community controls. Reduced prostate cancer risk was associated with high erythrocyte phosphatidylcholine levels of EPA (multivariate relative risk = 0.59; 95% confidence interval 0.37-0.95, upper vs lowest quartile) and DHA (multivariate relative risk = 0.62; 95% confidence interval 0.39-0.98, upper vs lowest quartile). These analyses support evidence from in vitro experiments for a reduced risk of prostate cancer associated with dietary fish oils, possibly acting via inhibition of arachidonic acid-derived eicosanoid biosynthesis.

A population-based study of clinical and pathological prognostic characteristics of men with familial and sporadic prostate cancer.

OBJECTIVES: To compare traditional prognostic characteristics of familial vs sporadic prostate cancers and to investigate potential detection biases arising from differences in the use of screening and investigative procedures. PATIENTS AND METHODS: Familial and sporadic cancers were identified in a population-based sample of incident prostate cancers (total 318) in Auckland, New Zealand. To examine the potential for detection biases in these comparisons, the sociodemographic and clinical characteristics were determined according to family history status for a sample of 959 patients newly referred to Auckland urology clinics by general practitioners for the investigation of prostate-related conditions. RESULTS: Compared with sporadic prostate cancers, familial cancers were more likely to be diagnosed in patients at a younger age (P=0.05), after asymptomatic serum prostate-specific antigen (PSA) screening (P=0. 02), and to include a lower proportion with extraprostatic disease (P=0.009) and serum PSA levels before diagnosis of >20 ng/mL (P=0. 04). This was consistent with the observed trend for patients referred to urology clinics with a positive family history to be of higher socio-economic and educational status and to more frequently undergo screening and biopsy investigation. CONCLUSION: Familial prostate cancers appeared to be diagnosed at an earlier stage of disease progression in this study population, possibly as the result of the higher socio-economic status and greater use of screening and investigative procedures amongst patients reporting a positive family history. These features reduce the validity of cross-sectional comparisons of prognostic variables for familial vs sporadic prostate cancer and emphasize the need for further longitudinal prognostic studies.

Passive smoking as well as active smoking increases the risk of acute stroke.

OBJECTIVE: To estimate the relative risk of stroke associated with exposure to environmental tobacco smoke (ETS, passive smoking) and to estimate the risk of stroke associated with current smoking (active smoking) using the traditional baseline group (never-smokers) and a baseline group that includes lifelong non-smokers and long-term (> 10 years) ex-smokers who have not been exposed to ETS. DESIGN AND SETTING: Population-based case-control study in residents of Auckland, New Zealand. SUBJECTS: Cases were obtained from the Auckland stroke study, a population-based register of acute stroke. Controls were obtained from a cross-sectional survery of major cardiovascular risk factors measured in the same population. A standard questionnaire was administered to patients and controls by trained nurse interviewers. RESULTS: Information was available for 521 patients with first-ever acute stroke and 1851 community controls aged 35-74 years. After adjusting for potential confounders (age, sex, history of hypertension, heart disease, and diabetes) using logistic regression, exposure to ETS among non-smokers and long-term ex-smokers was associated with a significantly increased risk of stroke (odds ratio (OR) = 1.82; 95% confidence interval (95% CI) = 1.34 to 2.49). The risk was significant in men (OR = 2.10; 95% CI = 1.33 to 3.32) and women (OR = 1.66; 95% CI = 1.07 to 2.57). Active smokers had a fourfold risk of stroke compared with people who reported they had never smoked cigarettes (OR = 4.14; 95% CI = 3.04 to 5.63); the risk increased when active smokers were compared with people who had never smoked or had quit smoking more than 10 years earlier and who were not exposed to ETS (OR = 6.33; 95% CI = 4.50 to 8.91). CONCLUSIONS: This study is one of the few to investigate the association between passive smoking and the risk of acute stroke. We found a significantly increased risk of stroke in men and in women. This study also confirms the higher risk of stroke in men and women who smoke cigarettes compared with non-smokers. The stroke risk increases further when those who have been exposed to ETS are excluded from the non-smoking reference group. These findings also suggest that studies investigating the adverse effects of smoking will underestimate the risk if exposure to ETS is not taken into account.

A prospective cohort study of blood donors: methodological issues in the investigation of injuries and chronic diseases.

Blood donors have made important contributions to research, most notably in cross-sectional seroprevalence studies. The proposed New Zealand Blood Donors Health Study is a prospective cohort study of 30,000 New Zealand donors designed to investigate the determinants of common injuries, cardiovascular disease and cancer. While robust from an analytic perspective, the execution of prospective cohort studies in many settings is impeded by methodological, economic and organisational barriers. We examined the operational considerations of implementing a large-scale cohort study at a transfusion centre and evaluated measures taken to optimise data collection procedures. A pilot study of 1,000 participants revealed donor motivation to participate in this research was high (91% response rate). Comprehensive exposure data on lifestyle, behavioural and psychosocial factors were obtained from 95% of participants. Substantial heterogeneity in levels of potential risk factors was noted among respondents. Detailed dietary habit information and a study blood sample were obtained from 67% and 100% of participants, respectively. Study recruitment and baseline data collection was feasible during routine donor visits with minimal interruption to donor centre staff and procedures. We conclude the study design and characteristics of the regional donor program enhance the efficiency and significance of the proposed research.

Non-steroidal anti-inflammatory drugs and prostate cancer progression.

Experimental studies have suggested that the biosynthesis of arachidonic acid-derived eicosanoids such as prostaglandin E2 via the cyclo-oxygenase pathway may play a significant role in supporting cell proliferation in human prostate cancer cell lines. However, the aetiological significance of this for clinical prostate cancer has remained unclear. In particular, the potential for prostate cancer chemoprevention using nonsteroidal anti-inflammatory drugs (cyclo-oxygenase inhibitors; NSAIDs) has received little attention. The purpose of our study was to investigate associations between prostate cancer risk and use of NSAIDs. A population-based case-control study was carried out over 13 months from 1996 in metropolitan Auckland, New Zealand. A total of 317 newly diagnosed prostate cancer cases (including 192 "advanced" cases) representative of all cancer cases in the study population were identified from urology clinic referrals and histology reports. A total of 480 age-matched controls were recruited following random selection from the study population using electoral rolls as the sampling frame. After adjusting for potential confounding by socio-economic status and dietary fat consumption, there was a trend toward reduced risks of advanced prostate cancer associated with regular use of total NSAIDs (RR = 0.73; 95% CI 0.50-1.07) and total aspirin (RR = 0.71; 95% CI 0.47-1.08). However, these associations failed to reach statistical significance at the usually accepted levels. Weaker inverse associations were found for total prostate cancers, which included a number of small, low-grade tumours of less clinical significance. These findings lend support to proposed underlying aetiological hypotheses which imply a role for cyclo-oxygenase activity in prostate cancer progression.