Biomedical subjects

Mark L Divitini

Publications and source records attributed to Mark L Divitini.

10 recordsLinked to original sources

PubMed2006

Population-based study of the relationship between mutations in the hemochromatosis (HFE) gene and arthritis.

BACKGROUND AND AIM: Mutations in the hemochromatosis (HFE) gene are carried by one in three individuals of British Isles descent and may result in increased iron stores. These increased iron stores could potentially induce or exacerbate diseases, such as arthritis, in which iron has a role in pathogenesis. Although arthritis is a well-known association of clinically overt hereditary hemochromatosis, controversy surrounds the role of mutations in the HFE gene as risk factors for arthritis. The aim of the present study was to determine whether mutations in the HFE gene are associated with an increased prevalence of arthritis. METHODS: A population-based study was conducted in Busselton, Western Australia, of the prevalence of arthritis in 1372 individuals of British Isles descent. Participants completed a questionnaire and general physical examination. Analysis for C282Y and H63D HFE mutations was undertaken. Unadjusted and adjusted odds ratios (OR) were calculated for the relationship between HFE mutations and the prevalence of self-reported, doctor-diagnosed arthritis. RESULTS: There was no association between the presence of HFE mutations and the prevalence of self-reported, doctor-diagnosed arthritis (C282Y/wild type (WT) adjusted OR = 1.041 (95% confidence interval (CI) 0.68-1.61), H63D/WT OR = 0.76 (95% CI 0.53-1.08), C282Y/C282Y OR = 0.39 (95% CI 0.04-3.63), C282Y/H 63D OR = 0.808 (95% CI 0.27-2.42), H63D/H63D OR = 0.419 (95% CI 0.13-1.36)). Overall adjusted OR for arthritis in participants with one or more HFE mutations was 0.81 (95% CI 0.61-1.09). CONCLUSIONS: Mutations of the HFE gene are not risk factors for arthritis in populations of British Isles descent.

Adult↗

PubMed2005

Folate levels and cancer morbidity and mortality: prospective cohort study from Busselton, Western Australia.

PURPOSE: To test a community population for the hypothesis that carcinogenesis is related to blood folate levels. METHODS: Prospective analysis of cancer mortality data for a cohort of 964 men (person-time follow up: 20,254 years) and 1024 women (person-time follow up: 24,970 years) and morbidity data for a subcohort, all of whom participated in the 1969 Busselton (Western Australia) Health survey. Outcome measures were adjusted hazard ratios according to baseline folate levels for total cancer mortality and morbidity and site specific mortality and morbidity for colorectal, lung, breast, and prostate cancers. RESULTS: In total, there were 278 cancer deaths--45 from colorectal cancer, 44 from lung cancer, 15 from breast cancer, and 31 from prostate cancer. Decreased serum folate levels showed an independent association with increased prostate cancer mortality risk, the adjusted hazard ratio per decrease of 2 microg/L was 1.56 (CI: 1.05, 2.38), men whose levels were in the lowest quartile had an adjusted hazard ratio of 4.79 (CI: 1.56, 14.43) for subsequent death from prostate cancer. The morbidity subcohort data showed that decreased red blood-cell folate was significantly associated with increased events due to breast cancer, the adjusted hazard ratio per decrease of 100 mug/L was 1.96 (CI: 1.22, 3.12), women in the lowest quartile of red cell folate levels had an adjusted hazard ratio of 6.46 (CI: 1.19, 35.07) for a subsequent breast cancer event. Mortality and morbidity from colorectal or lung cancers were not associated with folate levels. CONCLUSIONS: Independent associations, assessed over periods greater than 20 years, were demonstrated between decreased folate levels and increased risks of prostate cancer mortality and breast cancer morbidity.

Adult↗

PubMed2005

Spouse selection and environmental effects on spouse correlation in lung function measures.

PURPOSE: Concordance between spouses may be due to partner selection factors and/or the effects of marriage/environment. The extent to which partner selection factors contribute to spouse concordance has important implications for heritability studies. The aim of this study was to examine the magnitude of spouse correlation in lung function measures and its relationship to duration of marriage. METHODS: Cross-sectional and longitudinal data collected over the period 1969 to 1995 for 2615 couples from the Busselton Health Study have been analyzed using the program FISHER. RESULTS: Unadjusted correlations were around 0.45 for forced expiratory volume in 1 second (FEV1) and 0.25 for FEV1/FVC (forced vital capacity) and were reduced to 0.05 and 0.10, respectively, after adjustment for age, height, and smoking. No trend with marriage duration was apparent in both cross-sectional and longitudinal analyses but there was a significant downward trend in the correlations with age at marriage. CONCLUSIONS: The findings indicate that observed correlations in lung function measures are mostly due to partner selection factors and that partner selection factors have greater influence for couples that marry at younger ages. Family studies that aim to identify and separate genetic from other influences on lung function measures should not regard the mother-father correlation as due to common environment effects.

Adult↗

PubMed2005

Effects of HFE gene mutations and alcohol on iron status, liver biochemistry and morbidity.

BACKGROUND AND AIMS: The aims of the present study were to determine: (i) whether alcohol consumption is greater in individuals with HFE mutations; and (ii) whether common HFE mutations modify the effects of alcohol on serum iron and liver biochemistry or morbidity. METHODS: The residents of the town of Busselton in Western Australia were subject to cross-sectional health surveys between 1966 and 1983. In 1994/1995 all surviving participants of the earlier surveys were invited to take part in a follow-up survey. Logistic, linear and Poisson log-linear regression analyses were performed in 1490 men and 1452 women from the 1994/1995 survey to assess the relationships between HFE mutations, alcohol, iron levels, liver biochemistry and morbidity. RESULTS: Heavy or moderate alcohol consumption was present in 7% or 36% of men and 0.5% or 12% of women, respectively. Alcohol consumption strongly influenced levels of serum ferritin and gamma glutamyl transpeptidase (GGT) and mean cell volume (MCV) in men and women but only alanine aminotransferase (ALT) levels in women. These effects were independent of HFE gene mutations. Hospital admission rates for respiratory disorders were higher in men with the C282Y mutation. CONCLUSIONS: Alcohol consumption strongly influences serum ferritin and GGT levels and MCV in men and women but only ALT levels in women, and these effects are independent of HFE mutations. HFE gene mutations do not predispose to moderate or heavy alcohol consumption. The C282Y mutation is associated with increased respiratory admission rates in men.

Alanine Transaminase↗

PubMed2005

Correlates of habitual snoring and witnessed apnoeas in Busselton, Western Australia.

OBJECTIVE: The aim of this study was to identify potential body size, behavioural and respiratory risk factors for habitual snoring and witnessed apnoeas in a general population. METHODS: Correlates of these conditions were studied in a sample of 3,577 adults aged 25-74 years who participated in a comprehensive health survey in Busselton, Western Australia, during 1994/95. Logistic regression was used to assess associations after age and gender adjustment and also in multivariate models. RESULTS: The prevalence of both conditions was higher in men and rose with age. After controlling for age, gender and body mass index no additional body size variable remained significantly associated with witnessed apnoeas, whereas both waist-hip ratio and neck-height ratio remained significantly associated with habitual snoring. Among behavioural variables, smoking showed the strongest association, and among respiratory symptoms, asthma for habitual snoring and bronchitis for witnessed apnoeas had significant independent associations. CONCLUSIONS AND IMPLICATIONS: This study has confirmed obesity and smoking as key determinants of habitual snoring and witnessed apnoeas. It has also shown that a number of measures of obesity are independently related to habitual snoring and that asthma and bronchitis may also play a role, independently of obesity.

Adult↗

PubMed2004

Is sialic acid an independent risk factor for cardiovascular disease? A 17-year follow-up study in Busselton, Western Australia.

PURPOSE: To investigate the relationship between serum sialic acid level and risk of coronary heart disease (CHD) and stroke in men and women without diagnosed cardiovascular disease. METHODS: A prospective case-cohort study over the period 1981 to 1998 involving 151 CHD cases, 87 stroke cases, and a random sub-cohort of 340 was used. Sialic acid levels were determined by enzymatic method from frozen serum. Cox proportional hazards regression was used to estimate the relative risks of CHD and stroke for sialic acid tertiles and for continuous sialic acid level after adjustment for age, blood pressure, body mass index, cholesterol, triglycerides, diabetes, and smoking. RESULTS: The multivariate-adjusted relative risk of CHD associated with a 25 mg/dl increase in sialic acid was 1.22 (95% CI: 1.02-1.45) overall, 1.40 (95% CI: 1.11-1.76) in women, and 1.06 (95% CI: 0.82-1.37) in men. The overall relative risk for stroke was 1.13 (95% CI: 0.87-1.46) and for CHD and stroke combined it was 1.17 (95% CI: 0.99-1.37) CONCLUSIONS: Serum sialic acid may be a long-term predictor of CHD events in adults (especially women) who are currently clinically free of cardiovascular disease. Further studies are needed to determine whether this association can be explained by sialic acid being a marker of accelerated atherosclerosis or inflammation.

Adult↗

PubMed2004

Homocysteine and cardiovascular disease: a 17-year follow-up study in Busselton.

STUDY OBJECTIVE: Prospective assessment of serum homocysteine level in relation to risk of coronary heart disease (CHD) and stroke. DESIGN: Case-cohort study with 17 years follow up. METHODS: Homocysteine was measured from stored serum. Proportional hazards regression models were used to obtain adjusted hazard ratios. RESULTS: There was no significant overall relationship between homocysteine and cardiovascular disease after controlling for known confounders. For women, removal of creatinine from the multivariate model resulted in a significant relationship. CONCLUSIONS: These results provide little support for a significant independent relationship between level of homocysteine and risk of CHD or stroke in men and women with no evidence of pre-existing cardiovascular disease.

Adult↗

PubMed2003

Allergy, atopy, and cancer: a prospective study of the 1981 Busselton cohort.

The associations among certain allergic disorders, atopy upon skin-prick testing, and specific cancers were evaluated in a prospective study. Information regarding history of asthma and hay fever was collected by questionnaire from 3,308 cancer-free participants in the 1981 Busselton Health Survey. A subset of 1,005 participants also underwent skin-prick testing. The cohort was followed for a new diagnosis of cancer or death until the end of 1999. Cox proportional hazards regression analysis was used to estimate adjusted hazard ratios (relative risks) for breast, prostate, colorectal, lung, and hematologic cancers and melanoma. Having a skin reaction to house dust mites nearly tripled the risk of prostate cancer (relative risk = 2.90, 95% confidence interval: 1.26, 6.68). History of asthma and hay fever were associated with a trend toward a reduced risk of colorectal cancer and increased risk of leukemia, but these results were not statistically significant. Hay fever was associated with melanoma risk in men but not in women. No association was found between breast and lung cancers and allergic disorders or atopy.

Allergens↗

PubMed2003

A prospective study of infection and cardiovascular diseases: the Busselton Health Study.

BACKGROUND: Infectious agents might play a role in the aetiology of cardiovascular diseases. The aim was to determine the association of antibodies to implicated infectious agents with coronary heart disease (CHD) and stroke in a population-based prospective study. DESIGN: This study was based on a cohort of 1612 cardiovascular disease-free adults in the 1981 Busselton Health Survey. Primary risk factors were measured from stored serum and case-cohort sampling was used to reduce costs and preserve serum. The outcomes of interest were time to first CHD or stroke event. Serum antibody tests were carried out for all 218 CHD cases, all 119 stroke cases and a random subset of 451 subjects. METHODS: Sera were tested for antibodies to Chlamydia pneumoniae (IgG and IgA), and for IgG antibodies to Helicobacter pylori and cytomegalovirus (CMV). The association between serum antibody and risk of cardiovascular diseases was analysed using Cox proportional hazards regression. RESULTS: The estimated population prevalence was 24% for C. pneumoniae IgG, 7% for C. pneumoniae IgA, 58% for H. pylori and 85% had CMV antibody levels greater than 15 AU/mL. The estimated relative risk of CHD was around 1.2 for all antibodies examined, except for C. pneumoniae IgA for which it was less than one, and the estimated relative risk of stroke was around 0.85, however in all cases the 95% confidence interval included one. CONCLUSIONS: This study of an Australian population does not support an association between serum antibody levels to C. pneumoniae, H. pylori and CMV with development of cardiovascular diseases.

Adult↗

PubMed2002

Effects of body iron stores and haemochromatosis genotypes on coronary heart disease outcomes in the Busselton health study.

BACKGROUND: Increased iron stores and haemochromatosis gene mutations may be risk factors for coronary heart disease. The aims of this study were to determine in a stable community population whether increased iron stores or haemochromatosis gene mutations were risk factors for coronary heart disease. DESIGN: Cross-sectional and prospective cohort studies. METHODS: We evaluated 1185 men and 1141 women aged 20-79 years of predominantly Anglo-Celtic descent from the 1994-95 assessment of the Busselton population in Western Australia. Subjects underwent haemochromatosis genotyping, serum iron studies, clinical, biochemical and ECG evaluation for coronary heart disease and associated risk factors. Hospital admissions or death from cardiovascular disease were determined by linkage with the Western Australian morbidity and mortality database. The study design was cross-sectional for the 1994-95 cohort comparing coronary heart disease cases with unaffected subjects and unaffected subjects were followed prospectively until December 1998. RESULTS: Cross-sectional and prospective cohort analyses demonstrated that elevated serum iron parameters or possession of either the C282Y or H63D mutations in the gene were not predictive of increased risk for coronary heart disease in men or women. CONCLUSIONS: Increased iron stores or haemochromatosis gene mutations are not significant risk factors for coronary heart disease.

Adult↗