Gemma Browne

CKD Prevalence Varies across the European General Population

CKD prevalence estimation is central to CKD management and prevention planning at the population level. This study estimated CKD prevalence in the European adult general population and investigated international variation in CKD prevalence by age, sex, and presence of diabetes, hypertension, and obesity. We collected data from 19 general-population studies from 13 European countries. CKD stages 1-5 was defined as eGFR<60 ml/min per 1.73 m(2), as calculated by the CKD-Epidemiology Collaboration equation, or albuminuria >30 mg/g, and CKD stages 3-5 was defined as eGFR<60 ml/min per 1.73 m(2) CKD prevalence was age- and sex-standardized to the population of the 27 Member States of the European Union (EU27). We found considerable differences in both CKD stages 1-5 and CKD stages 3-5 prevalence across European study populations. The adjusted CKD stages 1-5 prevalence varied between 3.31% (95% confidence interval [95% CI], 3.30% to 3.33%) in Norway and 17.3% (95% CI, 16.5% to 18.1%) in northeast Germany. The adjusted CKD stages 3-5 prevalence varied between 1.0% (95% CI, 0.7% to 1.3%) in central Italy and 5.9% (95% CI, 5.2% to 6.6%) in northeast Germany. The variation in CKD prevalence stratified by diabetes, hypertension, and obesity status followed the same pattern as the overall prevalence. In conclusion, this large-scale attempt to carefully characterize CKD prevalence in Europe identified substantial variation in CKD prevalence that appears to be due to factors other than the prevalence of diabetes, hypertension, and obesity.

Methodology used in studies reporting chronic kidney disease prevalence: a systematic literature review

Background Many publications report the prevalence of chronic kidney disease (CKD) in the general population. Comparisons across studies are hampered as CKD prevalence estimations are influenced by study population characteristics and laboratory methods. Methods For this systematic review, two researchers independently searched PubMed, MEDLINE and EMBASE to identify all original research articles that were published between 1 January 2003 and 1 November 2014 reporting the prevalence of CKD in the European adult general population. Data on study methodology and reporting of CKD prevalence results were independently extracted by two researchers. Results We identified 82 eligible publications and included 48 publications of individual studies for the data extraction. There was considerable variation in population sample selection. The majority of studies did not report the sampling frame used, and the response ranged from 10 to 87%. With regard to the assessment of kidney function, 67% used a Jaffe assay, whereas 13% used the enzymatic assay for creatinine determination. Isotope dilution mass spectrometry calibration was used in 29%. The CKD-EPI (52%) and MDRD (75%) equations were most often used to estimate glomerular filtration rate (GFR). CKD was defined as estimated GFR (eGFR) <60 mL/min/1.73 m2 in 92% of studies. Urinary markers of CKD were assessed in 60% of the studies. CKD prevalence was reported by sex and age strata in 54 and 50% of the studies, respectively. In publications with a primary objective of reporting CKD prevalence, 39% reported a 95% confidence interval. Conclusions The findings from this systematic review showed considerable variation in methods for sampling the general population and assessment of kidney function across studies reporting CKD prevalence. These results are utilized to provide recommendations to help optimize both the design and the reporting of future CKD prevalence studies, which will enhance comparability of study results.

DASH Diet Score and Distribution of Blood Pressure in Middle-Aged Men and Women

BACKGROUND The Dietary Approaches to Stop Hypertension (DASH) Trial provides critical data on the impact of a specific diet pattern (low in salt, fat, and processed foods and high in fruit and vegetables) on blood pressure (BP). The effect of compliance with a DASH-type diet on BP in a general population sample is less well defined. We studied associations between a DASH style diet and BP. METHODS We used cross-sectional data from a study of men and women aged 47-73 years (n = 2,047). Participants completed a physical examination that included 3 standardized clinical BP recordings. A subsample (n = 1,187) had ambulatory BP measurements (ABPM) taken. Diet was assessed using a DASH dietary score constructed from a standard Food Frequency Questionnaire. Lower scores indicated less healthy diets. Hypertension was defined as clinic BP ≥ 140/90 mm Hg on medication or as 24-hour ABPM ≥ 130/80 mmHg. RESULTS Inverse associations were evident between DASH and systolic BP (SBP). There was a difference in clinic SBP of 7.5 mm Hg and 5.1 mm Hg and a difference in ABPM SBP of 6.3mm Hg and 5.4mm Hg in men and women, respectively, between the highest and lowest DASH quintiles. In fully adjusted multivariable regression analysis, DASH score was inversely associated with SBP. Clear population differences in SBP were evident across DASH quintiles. CONCLUSIONS The observed associations indicate that the findings are consistent with the hypothesis that adherence to DASH-equivalent diet can reduce BP at the population level. Public policy promoting a DASH-style healthy diet could have a significant impact on population health by reducing average BP in the population.

Prevalence of diminished kidney function in a representative sample of middle and older age adults in the Irish population.

BackgroundThe prevalence of chronic kidney disease (CKD) using available estimating equations with the Republic of Ireland is unknown.MethodsA randomly selected population based cross-sectional study of 1,098 adults aged 45 years and older was conducted using data from the 2007 Survey of Lifestyle, Attitudes and Nutrition (SLÁN). Estimated Glomerular Filtration Rate (eGFR) was calculated from a single IDMS aligned serum creatinine using the CKD-EPI and the MDRD equations, and albumin to creatinine ratio was based on a single random urine sample.ResultsThe sample clinical characteristics and demography was similar to middle and older age adults in the general Irish population, though with an underrepresentation of subjects >75 years and of males. All results are based on subjects with available blood and urine samples. Applying weighting to obtain survey based population estimates, using Irish population census data, the estimated weighted prevalence of CKD-EPI eGFR<60 mL/min/1.73m2 was 11.6%, (95% confidence interval; 9.0, 14.2%), 12.0% ( 9.0, 14.2%) of men and 11.2% (7.3, 15.2%) of women. Unweighted prevalence estimates were similar at 11.8% (9.9, 13.8%). Albuminuria increased with lower CKD-EPI eGFR category. 10.1% of all subjects had albuminuria and an eGFR≥60 mL/min/1.73 m2 giving an overall weighted estimated prevalence of National Kidney Foundation (NKF) defined CKD 21.3% (18.0, 24.6%), with the unadjusted estimate of 21.9% (19.5, 24.4%). MDRD related estimates for eGFR <60 mL/min/1.73 m2, and NFK defined CKD were higher than CKD-EPI and differences were greater in younger and female subjects.ConclusionsCKD is highly prevalent in middle and older aged adults within the Republic of Ireland. In this population, there is poor agreement between CKD-EPI and MDRD equations especially at higher GFRs. CKD is associated with lower educational status and poor self rated health.

Validation of diet and urinary excretion derived estimates of sodium excretion against 24-h urine excretion in a worksite sample.

BACKGROUND AND AIMS To validate diet and urinary excretion derived estimates of sodium intake against those derived from 24-h urine collections in an Irish manufacturing workplace sample. METHODS AND RESULTS We have compared daily sodium (Na) excretion from PABA validated 24-h urine collections with estimated daily sodium excretion derived from the following methods: a standard Food Frequency Questionnaire (FFQ), a modified 24-h dietary recall method, arithmetic extrapolations from morning and evening spot urine samples, predicted sodium excretion from morning and evening spot urine samples using Tanakas, Kawasakis and the INTERSALT formula. All were assessed using mean differences (SD), Bland-Altman plots, correlation coefficients and ROC Area under the Curve (AUC) for a cut off of ≥100 mmol of Na/day. The Food Choice at Work study recruited 802 participants aged 18-64 years, 50 of whom formed the validation sample. The mean measured 24-h urinary sodium (gold standard) was 138 mmol/day (8.1 g salt). At the group level, mean differences were small for both dietary methods and for the arithmetic extrapolations from morning urine samples. The Tanaka, Kawasaki and INTERSALT methods provided biased estimates of 24-h urinary sodium. R(2) values for all methods ranged from 0.1 to 0.48 and AUC findings from 0.57 to 0.76. CONCLUSION Neither dietary nor spot urine sample methods provide adequate validity in the estimation of 24-h urinary sodium at the individual level. However, group mean errors from dietary methods are small and random and compare favourably with those from spot urine samples in this population.

Changing dietary patterns and associated risk factors on trends in blood pressure levels in middle-aged Irish adults: a population-based study.

Changing dietary patterns and associated risk factors on trends in blood pressure levels in middle-aged Irish adults: a population-based study

PP16 The Contribution of Changes in Diet and other Risk Factors to recent Favourable Trends in Blood Pressure in Middle-Aged Irish Adults

Background Recent declines in cardiovascular mortality in Ireland and other developed countries are partially attributable to favourable secular trends in blood pressure (BP). However the underlying causes of these BP trends are not well defined. In particular, the contribution of changes in the dietary and other lifestyle determinants of population BP levels is unclear. We examined changes in distribution and determinants of systolic blood pressure (SBP) in middle-aged Irish adults over a 12 year period Methods Data are from two cross-sectional studies of men and women aged 47-73 years recruited from 17 General Practices in Cork and Kerry (N = 1018, response rate 70%) and from one large General Practice in Cork (N = 2047, response rate 67%) in 1998 and 2010 respectively. Similar procedures were used at both time points, including recruitment methods, exclusion criteria, health and lifestyle questionnaire, dietary assessment (food frequency questionnaire [FFQ]) and physical examination (height, weight and blood pressure). Dietary quality was assessed using the Dietary Approaches to Stop Hypertension (DASH) score constructed from the FFQ: higher scores indicating healthier diets. Changes in mean SBP were examined in linear regression models and are presented as means (95% CI). Results Mean SBP fell by 7.1 mmHG (138.0, 130.9) in men and 4.7 mmHG (133.0, 128.3) in women between 1998 and 2010. Adjusted for age, gender and education mean SBP, was 5.8 mmHG (-7.3, -4.5) lower in 2010 than in 1998. Average BMI increased from 27.8 (4.0) to 29.1 (4.1) in men and from 27.4 (4.6) to 28.0 (5.1) in women. By contrast diet quality improved over the period in men and women from 22.5 (4.4) to 27.6 (5.6) and from 23.5 (4.7) to 30.1 (5.6) respectively. Significant trends in physical activity (favourable), smoking (favourable), and alcohol intake (unfavourable) were observed. The proportion of the sample with doctor diagnosed hypertension increased from 25% to 29% over the 12 year period. Adjusting for age, gender, education, BMI, smoking and alcohol the change in mean SBP remained relatively unchanged. Adjusting for DASH diet score the mean SBP change it was reduced to 4.1 mmHG (-6.5, -1.7) and on further adjustment for doctor diagnosed hypertension it was reduced to 3.9 mmHG (-6.3, -1.6). Discussion The findings suggest that average blood pressures levels in the population are falling, despite increasing prevalence of obesity. Much of the change is due to improvements in diet.

OP28 Diet Quality and Blood Pressure in Middle-Aged Men and Women

Background Findings from both observational and experimental studies (including the DASH Trial -Dietary Approaches to Stop Hypertension) are consistent with a significant, causal role for dietary salt intake in the distribution of blood pressure (BP) in populations. The DASH diet quality score, based on the intervention arm in the DASH-trial, has emerged as a potentially useful measure of diet quality in adult populations. We have studied associations between DASH score and blood pressure, both clinic and 24 hour ambulatory measurements (ABPM) in middle-aged men and women. Methods We used cross-sectional data from two studies of men and women aged 50 to 69 years, recruited in 1998 (n=1018) and 2010 (n=2047). Participants completed a physical examination including three standardised clinical BP recordings and a general health and lifestyle questionnaire. A sub-sample (n=1189) in 2010 had 24hr ambulatory BP measurements (ABPM). Diet quality was assessed using a DASH score constructed from a standardised Willett FFQ. DASH scores were categorised into quintiles, with lower quintiles indicating less healthy diets. Hypertension was defined as clinic BP>140/90mmHg (mean of readings 2 and 3) and 24-hour ABPM >130/70mmHg. Results Clear inverse trends were seen between DASH scores and systolic (SBP) and diastolic (DBP) BP in clinic and ABPM recordings. The associations between DASH score and clinic BP were similar in the 1998 and 2010 datasets. In the 2010 data, clinic SBP increased by 7.5 mmHg in men and 5.1 mmHg in women between the highest and lowest DASH quintiles and 24-hour ABPM systolic BP increased by 6.3mmHg and 5.4mmHg in men and women respectively between the highest and lowest DASH quintiles. In fully adjusted analyses, the odds ratios (OR) for clinic hypertension and ABPM hypertension in participants with DASH score in the first relative to the fifth DASH score quintile were as follows: clinic hypertension: OR 1.60 (95% CI 0.9–2.8), ABPM hypertension: OR 4.2; 95 % CI [1.1–15.9]). Stratifying by gender, these trends persisted for men however they were attenuated for women. Conclusion This study provides evidence of criterion validity for the use of DASH score as a measure of diet quality, especially in the diet-hypertension relationship in men. Our findings are consistent with the hypothesis that dietary patterns exert effects beyond the sum of the component parts. Public policy promoting a DASH-style healthy diet could have a significant impact on population health by reducing average blood pressure in the population.

Potential cardiovascular mortality reductions in Ireland associated with specific food policy options

Objective To estimate the potential reduction in Irish cardiovascular (CVD) mortality possible by decreasing salt, trans fat and saturated fat consumption, and by increasing fruit and vegetable consumption. Methods The previously validated IMPACT Food Policy Model was used to estimate potential annual CVD mortality reductions associated with various dietary policy scenarios. Two scenarios were modelled. Firstly, a conservative scenario which involved a small reduction in salt intake by 1 g/day, trans-fat by 0.5% of energy intake, saturated fat by 1% energy intake and increasing fruit and vegetable intake by 1 portion per day. Secondly, a more substantial but politically feasible scenario that involved a reduction in salt intake by 3 g/day, trans-fat by 1% of energy intake, saturated fat by 3% energy intake and increasing fruit and vegetable intake by 3 portions per day. Population, mortality and dietary data for Irish adults aged 25–84 years were used. Results were stratified by 10 year age and sex. A probabilistic sensitivity analysis was undertaken. Best, maximum and minimum estimates were calculated using Monte Carlo simulation. Results The small, conservative changes in food policy could result in approximately 450 fewer cardiovascular deaths per year. This would comprise approximately 215 fewer coronary heart disease (CHD) deaths in men (min 167, max 286), approximately 60 fewer CHD deaths in women (min 45, max 76), approximately 115 fewer stroke deaths in men (min 92, max 146) and 65 fewer stroke deaths in women (min 50, max 79). Approximately 29% of the 450 fewer deaths could be attributable to decreased trans-fat consumption, 23% to decreased saturated fat, 23% to decreased salt consumption and 26% to increased fruit and vegetable consumption. The 450 fewer deaths would represent a 10% reduction in CVD mortality in Ireland. Modelling the more substantial but feasible food policy options, we estimated that CVD mortality could be reduced by up to 1250 deaths per year, representing a 25% decline in CVD mortality in Ireland. Conclusions A considerable CVD burden is attributable to the excess consumption of saturated fat, trans-fat, salt and insufficient fruit and vegetables. There are significant opportunities for Government and industry to reduce CVD mortality through effective, evidence-based food policies. In public health we urgently need to better understand the levers of public policy change. We can then more effectively bring decades of research on CVD aetiology to bear on actually reducing the burden of disease in the population.

P1-267 The potential impact of specific food policy changes on cvd mortality in Ireland

Objective To estimate potential reductions in Irish CVD mortality achievable through specific changes in average intakes of saturated fat, trans-fat, salt, fruit and vegetables. Methods A previously validated food policy model was used to estimate potential annual CVD mortality reductions associated with a conservative scenario. Specifically, a reduction in salt intake by 1 g/d, trans fat by 0.5% of energy intake, saturated fat by 1% energy intake and increasing fruit and vegetable intake by one portion per day. More substantial but politically feasible targets were also modelled. Results were stratified by age and sex. A probabilistic sensitivity analysis was undertaken using Monte Carlo simulation. Results Modest changes in food policy could result in approximately 450 fewer cardiovascular deaths per year. This includes approximately 215 fewer coronary heart disease (CHD) deaths in men (minimum 167, maximum 286), approximately 60 fewer CHD deaths in women (45, 76), approximately 115 fewer stroke deaths in men (92, 146) and 65 fewer stroke deaths in women (50, 79). Approximately, 29% of the 450 fewer deaths would be attributable to decreased trans fat consumption, 23% to decreased saturated fat, 23% to decreased salt consumption and 26% to increased fruit and vegetable consumption. The 450 fewer deaths would represent a 10% reduction in CVD mortality in Ireland. More substantial but feasible food policy changes could reduce CVD mortality by up to 1250 deaths (representing a 25% mortality reduction). Conclusions There are significant opportunities for Government and industry to reduce CVD mortality through evidence-based food policies.