Melbourne School of Population and Global Health - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 10
-
ItemWhich health-related quality of life score?: A comparison of alternative utility measures in patients with Type 2 diabetes in the ADVANCE trial(BMC, 2007-04-27)BACKGROUND: Diabetes has a high burden of illness both in life years lost and in disability through related co-morbidities. Accurate assessment of the non-mortality burden requires appropriate health-related quality of life and summary utility measures of which there are several contenders. The study aimed to measure the impact of diabetes on various health-related quality of life domains, and compare several summary utility measures. METHODS: In the ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation) study, 978 Australian patients with Type 2 diabetes completed two health-related quality of life questionnaires at baseline: the EQ-5D and the SF-36v2, from which nine summary utility measures were calculated, and compared. The algorithms were grouped into four classes: (i) based on the EQ-5D; (ii) using fewer items than those in the SF-12 (iii) using the items in the SF-12; and (iv) using all items of the SF-36. RESULTS: Overall health-related quality of life of the subjects was good (mean utility ranged from 0.68 (+/-0.08) to 0.85(+/-0.14) over the nine utility measures) and comparable to patients without diabetes. Summary indices were well correlated with each other (r = 0.76 to 0.99), and showed lower health-related quality of life in patients with major diabetes-related events such as stroke or myocardial infarction. Despite the smaller number of items used in the scoring of the EQ-5D, it generally performed at least as well as SF-36 based methods. However, all utility measures had some limitation such as limited range or ceiling effects. CONCLUSION: The summary utility measures showed good agreement, and showed good discrimination between major and minor health state changes. However, EQ-5D based measures performed as well and are generally simpler to use.
-
ItemEvent Rates, Hospital Utilization, and Costs Associated with Major Complications of Diabetes: A Multicountry Comparative Analysis(PUBLIC LIBRARY SCIENCE, 2010-02)BACKGROUND: Diabetes imposes a substantial burden globally in terms of premature mortality, morbidity, and health care costs. Estimates of economic outcomes associated with diabetes are essential inputs to policy analyses aimed at prevention and treatment of diabetes. Our objective was to estimate and compare event rates, hospital utilization, and costs associated with major diabetes-related complications in high-, middle-, and low-income countries. METHODS AND FINDINGS: Incidence and history of diabetes-related complications, hospital admissions, and length of stay were recorded in 11,140 patients with type 2 diabetes participating in the Action in Diabetes and Vascular Disease (ADVANCE) study (mean age at entry 66 y). The probability of hospital utilization and number of days in hospital for major events associated with coronary disease, cerebrovascular disease, congestive heart failure, peripheral vascular disease, and nephropathy were estimated for three regions (Asia, Eastern Europe, and Established Market Economies) using multiple regression analysis. The resulting estimates of days spent in hospital were multiplied by regional estimates of the costs per hospital bed-day from the World Health Organization to compute annual acute and long-term costs associated with the different types of complications. To assist, comparability, costs are reported in international dollars (Int$), which represent a hypothetical currency that allows for the same quantities of goods or services to be purchased regardless of country, standardized on purchasing power in the United States. A cost calculator accompanying this paper enables the estimation of costs for individual countries and translation of these costs into local currency units. The probability of attending a hospital following an event was highest for heart failure (93%-96% across regions) and lowest for nephropathy (15%-26%). The average numbers of days in hospital given at least one admission were greatest for stroke (17-32 d across region) and heart failure (16-31 d) and lowest for nephropathy (12-23 d). Considering regional differences, probabilities of hospitalization were lowest in Asia and highest in Established Market Economies; on the other hand, lengths of stay were highest in Asia and lowest in Established Market Economies. Overall estimated annual hospital costs for patients with none of the specified events or event histories ranged from Int$76 in Asia to Int$296 in Established Market Economies. All complications included in this analysis led to significant increases in hospital costs; coronary events, cerebrovascular events, and heart failure were the most costly, at more than Int$1,800, Int$3,000, and Int$4,000 in Asia, Eastern Europe, and Established Market Economies, respectively. CONCLUSIONS: Major complications of diabetes significantly increase hospital use and costs across various settings and are likely to impose a high economic burden on health care systems.
-
ItemMeasurement of absolute copy number variation reveals association with essential hypertension(BMC, 2014-07-15)BACKGROUND: The role of copy number variation (CNV) has been poorly explored in essential hypertension in part due to technical difficulties in accurately assessing absolute numbers of DNA copies. Droplet digital PCR (ddPCR) provides a powerful new approach to CNV quantitation. The aim of our study was to investigate whether CNVs located in regions previously associated with blood pressure (BP) variation in genome-wide association studies (GWAS) were associated with essential hypertension by the use of ddPCR. METHODS: Using a "power of extreme" approach, we quantified nucleic acids using ddPCR in white subjects from the Victorian Family Heart Study with extremely high (n = 96) and low (n = 92) SBP, providing power equivalent to 1714 subjects selected at random. RESULTS: A deletion of the CNVs esv27061 and esv2757747 on chromosome 1p13.2 was significantly more prevalent in extreme high BP subjects after adjustment for age, body mass index and sex (12.6% vs. 2.2%; P = 0.013). CONCLUSIONS: Our data suggests that CNVs within regions identified in previous GWAS may play a role in human essential hypertension.
-
ItemSelf-rated health scores predict mortality among people with type 2 diabetes differently across three different country groupings: findings from the ADVANCE and ADVANCE-ON trials(WILEY, 2020-08)AIMS: To explore whether there is a different strength of association between self-rated health and all-cause mortality in people with type 2 diabetes across three country groupings: nine countries grouped together as 'established market economies'; Asia; and Eastern Europe. METHODS: The ADVANCE trial and its post-trial follow-up were used in this study, which included 11 140 people with type 2 diabetes from 20 countries, with a median follow-up of 9.9 years. Self-rated health was reported on a 0-100 visual analogue scale. Cox proportional hazard models were fitted to estimate the relationship between the visual analogue scale score and all-cause mortality, controlling for a range of demographic and clinical risk factors. Interaction terms were used to assess whether the association between the visual analogue scale score and mortality varied across country groupings. RESULTS: The visual analogue scale score had different strengths of association with mortality in the three country groupings. A 10-point increase in visual analogue scale score was associated with a 15% (95% CI 12-18) lower mortality hazard in the established market economies, a 25% (95% CI 21-28) lower hazard in Asia, and an 8% (95% CI 3-13) lower hazard in Eastern Europe. CONCLUSIONS: Self-rated health appears to predict 10-year all-cause mortality for people with type 2 diabetes worldwide, but this relationship varies across groups of countries.
-
Item
-
ItemSocioeconomic position in young adulthood is associated with BMI in Australian families(OXFORD UNIV PRESS, 2016-06)BACKGROUND: Low socioeconomic position (SEP) is associated with increased cardiovascular (CV) disease risk, but the relative importance of SEP in childhood and adulthood, and of changes in SEP between these two life stages, remains unclear. Studies of families may help clarify these issues. We aimed to assess whether SEP in young adulthood, or change in SEP from childhood to young adulthood, was associated with five continuously measured CV risk factors. METHODS: We used data from 286 adult Australian families from the Victorian Family Heart Study (VFHS), in which some offspring have left home (n = 364) and some remained at home (n = 199). SEP (defined as the Index of Relative Socioeconomic Disadvantage) was matched to addresses. We fitted variance components models to test whether young adult SEP and/or change in SEP was associated with systolic blood pressure, diastolic blood pressure, body mass index (BMI), total cholesterol or high-density lipoprotein cholesterol, after adjustment for parental SEP and within-family correlation. RESULTS: An increase in SEP of 100 SEIFA units from childhood to adulthood was associated with a lower BMI (β = -0.49 kg/m(2), P < 0.01) only. CONCLUSIONS: These results suggest that a change in SEP in young adulthood is an important predictor of BMI, independent of childhood SEP.
-
ItemNo Preview AvailableNerve growth factor gene locus explains elevated renal nerve growth factor mRNA in young spontaneously hypertensive rats(LIPPINCOTT WILLIAMS & WILKINS, 1998-10)Nerve growth factor (NGF) controls the growth of sympathetic nerves and is increased in young spontaneously hypertensive rats (SHR). The NGF gene has been linked genetically with hypertension in the SHR strain and may explain high NGF mRNA levels. To test for genetic linkage between the NGF gene and its expression in vivo, we examined renal NGF mRNA levels in male SHR, control Donryu rats (DRY), and F2 rats derived from SHR and DRY at ages 2, 4, 10, and 20 weeks. Tail-cuff blood pressure was measured at 4, 10, and 20 weeks of age. NGF mRNA levels in SHR (NGF genotype: SS) were higher than those in DRY (NGF genotype: DD) at 2, 4, and 10 weeks of age (P<0.0001) but the same at 20 weeks of age. In the F2 generation, the S allele was associated with significantly (P=0.01) higher renal NGF mRNA levels at 2 weeks of age. Mean NGF mRNA levels fell (P=0.01) with age in F2 rats, and the difference between SS and DD genotype F2 rats diminished at older ages and was not significant. In F2 rats there was a positive correlation between the number of NGF S alleles inherited and tail-cuff pressure (P<0.007). Our findings indicate that the NGF locus is an important regulator of NGF mRNA levels. It is likely that mutations in or near the NGF gene explain in part high early NGF gene expression in SHR.
-
ItemNo Preview AvailableIndependent genetic susceptibility to cardiac hypertrophy in inherited hypertension(LIPPINCOTT WILLIAMS & WILKINS, 1998-03)Cardiac hypertrophy is a common but not inevitable complication of hypertension. Variation in heart size in hypertensives may reflect independent genetic susceptibility to cardiac hypertrophy. Using an experimental genetic model, we determined the location of quantitative trait loci responsible for cardiac hypertrophy and/or hypertension. We studied 182 F2 male animals derived from a cross of the spontaneously hypertensive rat and normotensive Donryu rats. Direct mean arterial pressure (MAP) and left ventricular (LV) mass were measured at 20 weeks of age, and DNA was obtained for linkage analysis. The estimated heritability of MAP was 62% and for LV mass expressed per unit of body weight (relative LV mass) was 76%. We used 185 polymorphic markers, with an average intermarker distance of 12.3 centimorgans for a genome-wide scan in a representative subgroup of 46 animals to identify preliminary quantitative trait loci, which were then mapped in all 182 male F2 rats. Two loci showed logarithm of the odds scores of > 4.0. One on chromosome 2, Lvm-1, was linked to relative LV mass but showed no evidence of linkage to MAP. Another locus on chromosome 1, Map-1, was linked to MAP. In the same region, a locus Lvm-2 was linked with relative LV mass. These data indicate the existence of a genetic locus on chromosome 2 of the spontaneously hypertensive rat that affects relative LV mass independently of blood pressure.
-
ItemNo Preview AvailablePersistent reduction in renal nerve growth factor mRNA after perindopril treatment of young spontaneously hypertensive rats(LIPPINCOTT WILLIAMS & WILKINS, 1998-02)Nerve growth factor (NGF) determines sympathetic innervation of target tissues, and NGF levels are increased in young spontaneously hypertensive rats (SHR). Angiotensin can affect NGF levels, and the persistent reduction in blood pressure after brief angiotensin-converting enzyme inhibition in young SHR may involve long-term changes in NGF and sympathetic innervation. We measured the relative abundance of renal NGF mRNA by reverse transcription-polymerase chain reaction in SHR during and after treatment from 6 to 10 weeks of age with vehicle, perindopril (3 mg/kg per day), the bradykinin B2 antagonist Hoe 140 (0.5 mg/kg per day), both perindopril and Hoe 140, or angiotensin II (Ang II; 200 ng/kg per minute). Glomerular filtration rates were estimated at 10 and 20 weeks of age. At 10 weeks of age, Ang II caused a significant (P<.01) increase and perindopril caused a significant (P<.01) decrease in renal NGF mRNA levels. Blockade of the bradykinin B2 receptor during perindopril treatment attenuated (P<.05) the reduction in NGF mRNA levels. Renal NGF mRNA (P=.005) and blood pressure (P<.001) remained significantly lower than control 10 weeks after perindopril treatment was stopped. The partial reduction in blood pressure at 20 weeks of age in rats that had received perindopril and Hoe 140 was not associated with any difference in renal NGF mRNA. Perindopril-induced long-term reduction in renal NGF mRNA levels may decrease sympathetic innervation and thereby contribute to the long-term posttreatment blood pressure reduction.
-
ItemNo Preview AvailableNerve growth factor gene and hypertension in spontaneously hypertensive rats(LIPPINCOTT WILLIAMS & WILKINS, 1996-02)OBJECTIVE: High blood pressure in spontaneously hypertensive rat (SHR) is associated with increased sympathetic innervation of key tissues, possibly as the result of increased nerve growth factor (NGF). The aim of this study was to test for genetic linkage of the NGF gene to high blood pressure. DESIGN: We studied NGF gene expression in young SHR and examined linkage of the NGF locus to mean arterial pressure in genetically segregating crosses of SHR and normotensive Donryu (DRY) rats. METHODS: NGF mRNA was measured by Northern blot, and a restriction fragment length polymorphism of the NGF gene revealed after digestion with the NsiI restriction enzyme was used to study inheritance. RESULTS: Levels of NGF mRNA were detected easily in the kidneys of 2-, 4- and 10-week-old SHR but not in age-matched DRY rats. In an F2 population, the blood pressure of rats homozygous for the DRY NGF allele was 6 mmHg less than in heterozygotes and 8 mmHg less than in rats homozygous for the SHR NGF allele (analysis of variance, P < 0.004). In backcross rats the blood pressure of NGF heterozygotes was not significantly different from that of SHR homozygotes. CONCLUSION: These results indicate differences in renal NGF mRNA in SHR during the development of hypertension and suggest that a genetic locus in or near the NGF gene contributes in a Mendelian dominant pattern to a significant increment in blood pressure in SHR.