Chronic condition risk factor change over time in a remote Indigenous community.

INTRODUCTION: This study sought to determine change in chronic condition risk factors in a remote Indigenous community following a 3-year period of community-led health promotion initiatives. METHODS: Data were compared between two cross-sectional surveys of Indigenous Australian community residents before and after health promotion activities, and longitudinal analysis of participants present at both surveys using multilevel mixed-effects regression. RESULTS: At baseline, 294 (53% women; mean age 35 years) participated and 218 attended the second survey (56% women, mean age 40 years), and 87 attended both. Body composition, blood pressure and urinary albumin-to-creatinine ratio remained stable between baseline and follow-up. After adjusting for age and sex, haemoglobin A1c significantly increased (from 57 to 63 mmol/mol (7.5% to 8.1%), p=0.021) for those with diabetes. Increases were also observed for total cholesterol (from 4.4 to 4.6 mmol/L, p=0.006) and triglycerides (from 1.5 to 1.6 mmol/L, p=0.019), and high-density lipoprotein cholesterol levels improved (from 0.98 to 1.02 mmol/L, p=0.018). Self-reported smoking prevalence was high but stable between baseline (57%) and follow-up (56%). Similar results were observed in the longitudinal analysis to the cross-sectional survey comparison. CONCLUSION: Community-led health promotion initiatives may have had some benefits on chronic condition risk factors, including stabilisation of body composition, in this remote Indigenous community. Given that less favourable trends were observed for diabetes and total cholesterol over a short time period and smoking prevalence remained high, policy initiatives that address social and economic disadvantage are needed alongside community-led health promotion initiatives.

Cystatin C estimated glomerular filtration rate and all-cause and cardiovascular disease mortality risk in the general population: AusDiab study.

AIMS: Uncertainties about the role of cystatin C-based estimated glomerular filtration rate (eGFR) in the prediction of cardiovascular disease (CVD) beyond traditional CVD risk factors remain. We assessed contributions of eGFR to CVD and mortality in the general population. METHODS: Using 14 year follow-up data on 9353 adults without a reported history of CVD from the Australian Diabetes, Obesity and Lifestyle study, we assessed the contributions of eGFR (assessed by cystatin C (eGFRcysC ) and serum creatinine (eGFRcr ) and albuminuria (uACR) to total and CVD mortality. RESULTS: After adjusting for age, sex, CVD risk factors and uACR, compared with an eGFRcysC >90 mL/min per 1.73 m2 , eGFRcysC <60 mL/min per 1.73 m2 was associated with 56% and 73% increases in the risks for all-cause and CVD mortality, respectively. The respective changes for the c-statistic when eGFRcysC was added to a risk prediction model were 0.003 (95% confidence interval: 0.001 to 0.005) and 0.002 (95% confidence interval: -0.001 to 0.006). The net proportion of non-events assigned a lower-risk category significantly improved with the addition of eGFR (non-event net reclassification index eGFRcr : 1.0% and eGFRcysC : 1.5%) for all-cause mortality, but for CVD mortality, improvements were only significant when eGFR was combined with uACR. The net proportion of events assigned a higher-risk category was not significantly improved. CONCLUSION: In our community-based cohort, reduced eGFRcysC was associated with all-cause and CVD mortality. The addition of chronic kidney disease measures to risk prediction models improved overall risk stratification among those at low risk as opposed to those at high baseline risk of mortality.

Comparison of creatinine and cystatin C based eGFR in the estimation of glomerular filtration rate in Indigenous Australians: The eGFR Study.

BACKGROUND: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation that combines creatinine and cystatin C is superior to equations that include either measure alone in estimating glomerular filtration rate (GFR). However, whether cystatin C can provide any additional benefits in estimating GFR for Indigenous Australians, a population at high risk of end-stage kidney disease (ESKD) is unknown. METHODS: Using a cross-sectional analysis from the eGFR Study of 654 Indigenous Australians at high risk of ESKD, eGFR was calculated using the CKD-EPI equations for serum creatinine (eGFRcr), cystatin C (eGFRcysC) and combined creatinine and cystatin C (eGFRcysC+cr). Reference GFR (mGFR) was determined using a non-isotopic iohexol plasma disappearance technique over 4h. Performance of each equation to mGFR was assessed by calculating bias, % bias, precision and accuracy for the total population, and according to age, sex, kidney disease, diabetes, obesity and c-reactive protein. RESULTS: Data were available for 542 participants (38% men, mean [sd] age 45 [14] years). Bias was significantly greater for eGFRcysC (15.0mL/min/1.73m2; 95% CI 13.3-16.4, p<0.001) and eGFRcysC+cr (10.3; 8.8-11.5, p<0.001) compared to eGFRcr (5.4; 3.0-7.2). Accuracy was lower for eGFRcysC (80.3%; 76.7-83.5, p<0.001) but not for eGFRcysC+cr (91.9; 89.3-94.0, p=0.29) compared to eGFRcr (90.0; 87.2-92.4). Precision was comparable for all equations. The performance of eGFRcysC deteriorated across increasing levels of c-reactive protein. CONCLUSION: Cystatin C based eGFR equations may not perform well in populations with high levels of chronic inflammation. CKD-EPI eGFR based on serum creatinine remains the preferred equation in Indigenous Australians.