Hypertension and kidney disease in Asia

PURPOSE OF REVIEW: Communicable diseases were traditionally the major cause of public health concern in Asian countries, most of which were less developed. With industrialization and associated lifestyle changes during the past few decades, however, noncommunicable diseases similar to those that affect Western societies have emerged in Asian countries. The purpose of the review was to examine recent evidence about the burden and factors associated with hypertension and chronic kidney disease (CKD) in Asian countries.RECENT FINDINGS: Hypertension has become one of the leading causes of mortality in Asia. Although its prevalence continues to rise, it remains under-diagnosed and under-treated. CKD is becoming increasingly common mainly due to an increase in risk factors such as high blood pressure, diabetes, and obesity. Treatment of advanced CKD is overwhelmingly burdensome in a resource poor environment. Barriers to early detection of CKD in Asians include the fact that equations to estimate the glomerular filtration rate have not been validated in this population, and the uncertainty about appropriate glomerular filtration rate cutoff values to define CKD.SUMMARY: Concerted efforts are needed to develop and implement cost-effective strategies for prevention and treatment of hypertension and CKD in Asian countries. More research is needed on these conditions in these populations

Prevalence, determinants, and management of chronic kidney disease in Karachi, Pakistan - a community based cross-sectional study.

BACKGROUND: Chronic kidney disease (CKD) is increasing being recognized as a global public health problem. However, there is dearth of information on the prevalence, determinants, and management of CKD from low- and middle-income countries. The objectives of the study were to determine the 1) prevalence of CKD; 2) socio-demographic and clinical factors associated with CKD; and 3) the existing management of these patients with regards to blood pressure control, and use of antihypertensive medications. METHODS: We conducted a cross-sectional study on 2873 participants aged ≥ 40 years in 12 representative communities in Karachi, Pakistan. The primary outcome was clinically significant CKD defined as estimated glomerular filtration rate (eGFR) \u3c60 mL/min/1.73 m2 estimated by CKD-EPI (CKD Epidemiology Collaboration) Pakistan equation (0.686 × CKD-EPI1.059) or urinary albumin to creatinine ratio ≥ 3 mg/mmol (i.e. KDOQI CKD stage G3, A2 or worse). RESULTS: The overall prevalence (95% CI) of CKD was 12.5% (11.4 - 13.8%). The factors independently associated with CKD were older age, hypertension, diabetes, elevated systolic blood pressure, raised fasting plasma glucose, raised triglycerides, and history of stroke (p\u3c0.05 for each). About 267 (74.4%, 69.5 - 78.8%) adults with CKD had concomitant hypertension. Of these, 130 (48.7%, 42.6 - 54.9%) were on antihypertensive medications, and less than 20% had their BP controlled to conventional target of ≤ 140/90 mm Hg, and only 16.9% (12.6 - 21.9%) were on blockers of renin-angiotensin system alone or in combination with other drugs. CONCLUSIONS: Clinically significant CKD is common among Pakistani adults. The conventional risk factors for CKD and poor control of blood pressure among patients with CKD highlight the need to integrate CKD prevention and management in the primary care infrastructure in Pakistan, and possibly neighbouring countries

Serum creatinine as marker of kidney function in South Asians: a study of reduced GFR in adults in Pakistan

Migrant populations of South Asian origin have a higher risk for chronic kidney disease than the native whites. Several formulas have been developed to estimate kidney function from serum creatinine concentration. However, none of these has been validated in the South Asian population, which generally has different muscle mass composition than whites. A population-based cross-sectional study was performed on 262 individuals who were aged \u3e or = 40 yr in Karachi, Pakistan. Reduced GFR was defined as creatinine clearance (Ccr) measured in 24-h urine collection of /min per 1.73 m2. Creatinine excretion was compared with age- and gender-matched white individuals by comparison of observed versus expected results on the basis of a formula using t test. The agreement among Cockcroft Gault (CG) Ccr and Modification of Diet in Renal Disease (MDRD) Study GFR equations was assessed by regression analyses, and the degree of accuracy of estimated versus measured GFR was determined. Mean (95% confidence interval) creatinine excretion was 1.7 (1.0 to 2.4) mg/kg per d lower than expected for age- and gender-matched white individuals (P \u3c 0.001). The coefficient of determination for measured Ccr on the logarithmic scale was 66.7 and 55.6% for the CG and MDRD Study equations, respectively. The proportion of estimates within 20, 30, and 50% of measured Ccr values was 47.7 versus 32.8% (P \u3c 0.001), 64.9 versus 49.6% (P \u3c 0.001), and 79.4 versus 72.9 (P = 0.07) for CG versus MDRD Study equations, respectively. Lower mean creatinine excretion in these individuals may explain, in part, suboptimal agreement between estimated versus measured GFR. Inclusion of terms for ethnic and racial groups other than white and black might improve the performance of GFR estimating equations

Albuminuria and kidney function as prognostic marker of left ventricular mass among South Asians with hypertension

We aimed to evaluate the association of albuminuria and estimated glomerular filtration rate (eGFR) at baseline and changes in these parameters with left ventricular mass index (LVMI) at 7 years in adults with hypertension from communities in Pakistan. A nested cohort of 539 hypertensives aged 40 years and older from a community-living population in Karachi, Pakistan, followed up for 7 years in the Control of Blood Pressure and Risk Attenuation trial. Urine spot albumin-to-creatinine ratio (UACR) and serum creatinine-based eGFR were assessed at baseline and 7 years, and echocardiography at 7 years. Mean age of participants was 50.9 ± 9.1 (standard deviation) years; 63% were female. Mean eGFR was 91.0 ± 15.9 (standard deviation) mL/min/1.73 m2 and median (interquartile range) UACR 6.2 (3.9, 11.3) mg/g. In multivariate analysis, although baseline eGFR was marginally associated with LVMI, a strong association was found between higher LVMI with greater rate of decline in eGFR (β = -1.05; 95% confidence interval [CI]: [-1.94, -0.17]). Higher baseline UACR was significantly associated with higher follow-up LVMI (β = 2.26; 95% CI: [0.87, 3.65]), as was rate of UACR increase of ≥1.07 mg/g/y versus of \u3c0.14 mg/g/y. (β = 4.19; 95% CI: [0.75, 7.63]). Associations with developing left ventricular hypertrophy were found for reduced baseline eGFR, higher baseline UACR, and greater rate of UACR increase, but not for rate of eGFR decline. Comparable results were observed for the outcomes of posterior wall thickness and septal wall thickness. Higher baseline albuminuria, lower baseline eGFR, and their longitudinal worsening were significantly associated with higher LVMI or the development of left ventricular hypertrophy among individuals with hypertension in Pakistan

Correlations of skin fold thickness and validation of prediction equations using DEXA as the gold standard for estimation of body fat composition in Pakistani children.

OBJECTIVE: To determine the correlation between dual energy X-ray absorptiometry (DEXA) and skin fold thickness (SKF) equations for estimation of body fat (BF) composition in secondary school children and validation of prediction equations by Slaughter, Goran and Dezenberg. DESIGN: Cross sectional analytical study. SETTING: Joint Commission for International Accredited (JCIA) tertiary care hospital of Karachi, Pakistan from January 2010 to May 2010. PARTICIPANTS: The study was approved by the Hospital\u27s ethical review committee. Written and verbal consents were obtained from principals of two schools and parents of 99 children (mean age of 14±1.89 years; min-max 9-19 years; 54 men and 45 women) accrued in study. DEXA scan was acquired and SKF was measured at angle of the scapula, iliac crest and mid-arm for bicep and tricep skin folds using Holtain Callipers. Correlations were established between estimated fat mass (FM) and per cent BF (%BF) calculated by DEXA and those predicted by prediction equations. On obtaining significant correlation of \u3e0.5, overall accuracy, precision and bias was calculated. RESULTS: There was an overall increased adiposity in females with FM of 3.57 kg and %BF 6.2% higher than male counterparts (p CONCLUSIONS: We conclude that Slaughter equation for estimating %BF showed reasonable validation with DEXA. Nevertheless further studies with consideration for maturity and ethnicity are warranted for better results. However, for estimation of FM, previously formulated equations by Goran and Dezenberg showed significant difference in our population. We do recommend further studies for developing and validation of skin fold equations specific to Pakistani paediatric populatio

Cost-effectiveness of community-based strategies for blood pressure control in a low-income developing country: findings from a cluster-randomized, factorial-controlled trial.

BACKGROUND: Evidence on economically efficient strategies to lower blood pressure (BP) from low- and middle-income countries remains scarce. The Control of Blood Pressure and Risk Attenuation (COBRA) trial randomized 1341 hypertensive subjects in 12 randomly selected communities in Karachi, Pakistan, to 3 intervention programs: (1) combined home health education (HHE) plus trained general practitioner (GP); (2) HHE only; and (3) trained GP only. The comparator was no intervention (or usual care). The reduction in BP was most pronounced in the combined group. The present study examined the cost-effectiveness of these strategies. METHODS AND RESULTS: Total costs were assessed at baseline and 2 years to estimate incremental cost-effectiveness ratios based on (1) intervention cost; (2) cost of physician consultation, medications, diagnostics, changes in lifestyle, and productivity loss; and (3) change in systolic BP. Precision of the incremental cost-effectiveness ratio estimates was assessed by 1000 bootstrapping replications. Bayesian probabilistic sensitivity analysis was also performed. The annual costs per participant associated with the combined HHE plus trained GP, HHE alone, and trained GP alone were $3.99,$3.34, and $0.65, respectively. HHE plus trained GP was the most cost-effective intervention, with an incremental cost-effectiveness ratio of$23 (95 confidence interval, 6-99) per mm Hg reduction in systolic BP compared with usual care, and remained so in 97.7 of 1000 bootstrapped replications. CONCLUSIONS: The combined intervention of HHE plus trained GP is potentially affordable and more cost-effective for BP control than usual care or either strategy alone in some communities in Pakistan, and possibly other countries in Indochina with similar healthcare infrastructure

Dietary Patterns and their Association with Hypertension Among Pakistani Urban Adults

Hypertension is one of the most common chronic diseases affecting more than 25% of adults worldwide. In Pakistan, 33% of the adult population suffers from hypertension. Numerous epidemiological studies have demonstrated the critical role of dietary patterns in the causation, prevention and management of hypertension. There’s a dearth of evidence from South Asia in this regard. The present study aimed to identify the association between dietary patterns and hypertension among 4304 low income urban adults who participated in the Control of Blood Pressure and Risk Attenuation (COBRA) study in Karachi, Pakistan. Dietary information was collected by a 33- item food frequency questionnaire and 3 unique dietary patterns namely; fat and sweet, fruit and vegetable, and seafood and yogurt patterns were derived using principal component factor analyses. We used univariate and multivariable logistic regression to examine the association between dietary patterns and hypertension. Men were more likely to have hypertension, while increase in age, and body mass index were also associated with hypertension (p\u3c0.001). After adjusting for age, gender, education, marital status, body mass index, and tobacco use; the seafood and yogurt pattern was less likely (OR=0.78: 95% CI: 0.63, 0.98; p-value 0.03) to be associated with hypertension, whereas no significant associations were seen for other two dietary patterns. These findings suggest that certain dietary patterns may be associated with hypertension among Pakistani low income urban adults

Do Dietary Patterns Explain High Prevalence of Cardiovascular Risk Factors Among Pakistani Urban Adults? A Cross-Sectional Study

Background The prevalence of cardiovascular disease (CVD) in South Asia is higher than in any other developing countries. The diversity of diets in populations among developing countries may be one explanation for the differences in CVD. This study was carried out to explore the association between dietary patterns and the presence of cardiovascular risk factors among Pakistani low income urban adults. Methods Socio demographic, physical activity and dietary information was collected from 1546 Pakistani subjects aged ≥40 years from the Control of Hypertension and Risk Attenuation (COBRA) study. Anthropometric, clinical and biomarker measures were assessed. Cluster analysis was used to identify dietary patterns from a food frequency questionnaire (FFQ) and multinomial regression was employed to investigate the association between dietary clusters and cardiovascular risk factors, using one of the dietary clusters as a reference category. Results The most prevalent CVD risk factors among participants were elevated low density lipoprotein- cholesterol (LDL-C) (69.8 %) and systolic blood pressure (SBP) (68.2 %), followed by central obesity (57.1 %), low levels of high density lipoprotein-Cholesterol (HDL-C) (56.3 %), overall obesity (46.0 %), high total cholesterol (32.3 %), and elevated fasting blood sugar (FBS) (34.9 %). The cluster analysis generated 3 non-overlapping diet patterns. Cluster 1(Traditional Pakistani Diet), was dominated by fruits, vegetables, milk products and chicken, included participants with high mean body mass index (BMI), waist circumference (WC), HDL-C and low mean SBP. Cluster 2 (Moderate Diet) reflected a moderate intake of most food items and included participants with significantly higher mean SBP. Cluster 3 (Fatty Diet) was characterized by high intake of beef, whole milk, paratha and lentils and those following this cluster had a low mean HDL-C and high SBP. In analyses controlling for age, gender, tobacco use and physical activity, participants in the Traditional diet cluster were more likely to be overweight (OR 1.39, 95 % CI 1.08 to 1.78) and high central adiposity (1.33, 95 % CI 1.04 to 1.71) than participants in the Moderate diet cluster, though less likely to have elevated SBP (OR 0.67, 95 % CI 0.51 to 0.86). LDL-C levels were higher in both the traditional Pakistani diet and Fatty diet cluster compared to the Moderate diet cluster. Low HDL-C was also more prevalent among the Traditional Pakistani diet cluster. Conclusion Among Pakistani population discernable diet patterns can be derived using clusters analysis. CVD risk factors prevalence differed by cluster membership, though relations for specific CVD risk are not consistent across clusters