the world health organization ( who ) has estimated that about 17 million people die annually from cardiovascular disease worldwide , which accounts for approximately 33% of all deaths .
in addition , 9.4 million deaths are attributed to complications of hypertension . according to who statistics in 2008 , hypertension was diagnosed in almost two - fifths of people aged 25 years and older worldwide .
if current trends continue , the number of patients with hypertension will increse by  500 million and reach a total of 1.56 billion in 2025 . 
 
there are about 639 million hypertensive people , which equals almost 75% of the population in developing countries with limited resources
. these hypertensive persons also have a very low awareness of their condition , as well as poor blood pressure ( bp ) control .
non - optimal bp control accounts for 66.6% of all strokes and 50% of coronary artery disease cases .
furthermore , hypertension is known to be one of the main risk factor of deaths in south asia . according to a study conducted between december 2011 and march 2012 in kabul , afghanistan the prevalence of hypertension was 46.2% for the age group of 40years and older . 
 
several epidemiological studies have reported an association between proteinuria and a poor prognosis in hypertensive patients .
the burden of proteinuria and its association with hypertension have not been studied in the adult hypertensive population of afghanistan .
therefore , this study was aimed at determining the prevalence of proteinuria , and the association of different variables with proteinuria , among adult hypertensive patients attending an outpatient clinic in afghanistan .
five hundred fifty - five patients with a high bp recorded at an outpatient clinic in andkhoy , afghanistan from december 2014 to may 2015 .
the case subjects included patients aged 18 years and older , who were receiving treatment for newly diagnosed arterial hypertension , defined as seated systolic / diastolic hypertension 140/90 mm hg at rest on the day of the study visit .
patients who had engaged in strenuous physical activity in the preceding 24 h , as well as female participants who were pregnant or menstruating , were ineligible because of the likely presence of false - positive results .
the subjects were evaluated during their clinic visit , and the study protocol included assessment of data obtained from each patient , including demographic characteristics , body mass index ( bmi ; weight in kilograms divided by height in meters squared ) , bp pattern , cardiovascular history , presence of cardiovascular risk factors , comorbidity and current drug - therapy .
the study was approved by the scientific review committee of balkh regional hospital . for this study ,
diabetes was defined as a fasting blood sugar level of  126 mg / dl , at the visit or self - reported use of hypoglycaemia medications .
the results were obtained by using the reagent tests strips of the accu - trend plus kit for cholesterol / glucose ( roche diagnostic usa ) . the definitions of obesity varies across studies , even among from the same country . for this study ,
overweight was defined as a bmi of 25 to < 30 kg/ m and obesity as bmi  30 .
dipstick screening for proteinuria and glycosuria were performed with the reagent strips ( roche diagnostic usa ) .
the urinary protein levels of dipstick urinary analyses were recorded as follows ; negative (  ) , trace ( + / ) or proteinuria ( 1 + , 2 + , 3 + or 4 + ) . cigarette smoking was assessed through a face to face interview .
patients were grouped into three categories : ( i ) patients who had smoked 100 cigarettes in his or her lifetime and currently smokes cigarettes ( current smoker ) ; ( ii ) patients who had smoked at least 100 cigarettes in his or her lifetime but had stopped smoking at the time of the interview ( past smokers ) ; ( iii ) patients who have never smoked , or who had smoked < 100 cigarettes in his or her lifetime ( non - smoker ) .
other factors that were considered were regular aerobic physical activity a minimum of 30 min for 5 days / week or vigorous physical activity for a minimum of 20 min for 3 days / week . the results from this measurement were entered onto each patient s case report form .
univariate and multivariate logistic regression analyses were performed to observe the association between proteinuria and the risk factors as well as target organ lesions .
odds ratios ( ors ) with 95% confidence intervals ( cis ) were estimated by using a logistic regression model .
all the prognostic valuables with p < 0.05 in a univariate logistic regression analysis were entered into a multivariate logistic regression analysis in order to determine independent predictors . a p value of < 0.05 was considered statistically significant .
all analyses were performed with the spss 20.0 software package ( spss , chicago , il , usa ) .
five hundred fifty - five patients with a high bp recorded at an outpatient clinic in andkhoy , afghanistan from december 2014 to may 2015 .
the case subjects included patients aged 18 years and older , who were receiving treatment for newly diagnosed arterial hypertension , defined as seated systolic / diastolic hypertension 140/90 mm hg at rest on the day of the study visit .
patients who had engaged in strenuous physical activity in the preceding 24 h , as well as female participants who were pregnant or menstruating , were ineligible because of the likely presence of false - positive results .
the subjects were evaluated during their clinic visit , and the study protocol included assessment of data obtained from each patient , including demographic characteristics , body mass index ( bmi ; weight in kilograms divided by height in meters squared ) , bp pattern , cardiovascular history , presence of cardiovascular risk factors , comorbidity and current drug - therapy .
the study was approved by the scientific review committee of balkh regional hospital . for this study ,
diabetes was defined as a fasting blood sugar level of  126 mg / dl , at the visit or self - reported use of hypoglycaemia medications .
the results were obtained by using the reagent tests strips of the accu - trend plus kit for cholesterol / glucose ( roche diagnostic usa ) . the definitions of obesity varies across studies , even among from the same country . for this study ,
overweight was defined as a bmi of 25 to < 30 kg/ m and obesity as bmi  30 .
dipstick screening for proteinuria and glycosuria were performed with the reagent strips ( roche diagnostic usa ) .
the urinary protein levels of dipstick urinary analyses were recorded as follows ; negative (  ) , trace ( + / ) or proteinuria ( 1 + , 2 + , 3 + or 4 + ) . cigarette smoking was assessed through a face to face interview .
patients were grouped into three categories : ( i ) patients who had smoked 100 cigarettes in his or her lifetime and currently smokes cigarettes ( current smoker ) ; ( ii ) patients who had smoked at least 100 cigarettes in his or her lifetime but had stopped smoking at the time of the interview ( past smokers ) ; ( iii ) patients who have never smoked , or who had smoked < 100 cigarettes in his or her lifetime ( non - smoker ) .
other factors that were considered were regular aerobic physical activity a minimum of 30 min for 5 days / week or vigorous physical activity for a minimum of 20 min for 3 days / week . the results from this measurement were entered onto each patient s case report form .
univariate and multivariate logistic regression analyses were performed to observe the association between proteinuria and the risk factors as well as target organ lesions .
odds ratios ( ors ) with 95% confidence intervals ( cis ) were estimated by using a logistic regression model .
all the prognostic valuables with p < 0.05 in a univariate logistic regression analysis were entered into a multivariate logistic regression analysis in order to determine independent predictors . a p value of < 0.05 was considered statistically significant .
all analyses were performed with the spss 20.0 software package ( spss , chicago , il , usa ) .
the mean age of the patients was 57.9  13.3 years ( range 1892 years ) .
most of the patients ( 59.1% ) were aged between 40 and 65 years , 222 were men ( 40.0% ) and 333 were women ( 60.0% ) .
the prevalence of current smokers among female patients ( 18.6% ) was significantly ( p < 0.001 ) lower than that among male patients ( 37.8% ) .
the prevalence of proteinuria was 67.2% and considerably higher in male than in female patients ( p < 0.001 ) . among all patients ,
14.9% had a family history of ischemic heart disease , 14.8% had family history of diabetes , and 53.4% had a family history of hypertension .
of these patients , 26.3% were current smokers , 33.7% had a bmi of 25 , 78.2% had uncontrolled bp , and 59.2% had regular physical exercise .  
fequency distribution of sociodemographic characteristics of study participants ( n=555 ) the mean age of patients in the proteinuria and non - proteinuria groups was 62.0  13.6 years and 57.7  13.4 years , respectively .
the male - to - female ratio in the proteinuria group was 1.15 and that in the nonproteinuria group was 2.81 .
smokers had higher rates of proteinuria than non - smokers 30.7% vs. 17.5% ( p = 0.03 ) .
patients with proteinuria had substantially increased levels of both systolic bp and diastolic bp ( 155.0  24.8 vs.146.2  24.0 mm hg , and 94.6  13.8 vs. 88.6  10.8 mm hg ; p < 0.001 , respectively ) .
the fasting blood glucose levels were 115.1  34.9 versus 104.5  23.7 ; p = 0.001 ) .
the prevalence of proteinuria was significantly higher among diabetic patients than non - diabetic patients ( 14.7% vs. 3.8% ; p < 0.001 ) .
patients with myocardial infarction had significantly higher proteinuria levels than those without myocardial infarction ( 25.7% vs.13.2% ; p = 0.001 ) .
proteinuria was more common in patients with heart failure ( 15.2% vs. 6.6% ; p = 0.04 ) .
physical activity was inversely associated with proteinuria ( 45.0% vs. 25.9% ; p < 0.001 ) .
there was also a considerable difference with regard to use of angiotensin - receptor blockers ( arbs ) , angiotensin - converting enzyme ( ace ) inhibitors , calcium channel blockers ( ccbs ) , and beta blockers ( bbs ) between patients with and those without proteinuria ( table 2 ) .  
comparison of factors associated with proteinuria among hypertensive patients multivariate logistic regression analysis was used to determine the association between proteinuria and smoking , heart failure , myocardial infarction , diabetes mellitus , stroke , hypercholesterolemia , and regular physical activity .
the odds of proteinuria among smokers were 1.88 times greater than those in non - smokers ( 95%ci 1.102.95 ) .
patients with heart failure had a more than two - fold increase in the odds of proteinuria than those without heart failure ( 95%ci 1.134.45 ) .
patients aged  65 years showed a 1.02 times increase of in the odds of proteinuria than those < 65 years ( 95%ci 1.001.04 ) .
the odds of proteinuria among diabetic patients were 3.41 times higher than those in patients without diabetes ( 95%ci 1.497.80 ) .
myocardial infarction , regular physical activity and diabetes mellitus were other variables that had a significant association with proteinuria in the univariate logistic regression model , however , in the multivariate model , this association was not significant ( table 3 ) .
there has been a lack of data about the prevalence of proteinuria in afghanistan , which is important information on the evaluation of hypertensive patients .
the presence of proteinuria helps in identifying patients who are at high risk and need to receive aggressive treatment for risk factors .
the prevalence of proteinuria among patients with hypertension in the northern part of afghanistan was 67.2% . a similar prevalence ,
67.8% was reported in morocco , as part of an i - search ( survey for evaluating microalbuminuria routinely by cardiologists in patients with hypertension ) study , in which the data were collected from 40 cardiology centers with a population of 476 patients . in another i - search study performed in turkey in an international multi - center
the study was designed to evaluate the frequency of microalbuminuria , which was observed in a large number of outpatient clinics , in a total of 21,050 patients that were receiving treatment for hypertension in 26 countries . however , in our study , the prevalence of proteinuria was higher than that seen in another study from a tertiary hospital in uganda ( 39.5% ) .
these differences are most likely associated with the different criteria used in patient selection , such as age , severity of hypertension , race , and coexisting cardiovascular risk factors ( e.g. , diabetes mellitus , renal disease , dyslipidemia , and obesity ) , as well as the technique used for proteinuria determination . moreover , in a study conducted in 26 countries , the highest rates of microalbuminuria were observed in asia . 
 
the prevalence of smoking among female patients was lower than that among male patients . a similar
this low prevalence of smoking among female patients may due to social factors that discourage smoking in women . in our study
, we found a significant association between proteinuria and the male which is comparable with the results of others studies .
this discrepancy is most probably due to a combination of risk factors ( i.e. , diabetes , smoking , and obesity ) and the fact that ischemic heart disease is more frequent in men than in women . in the present investigation , we found the association between high systolic bp and diastolic bp and proteinuria .
a similar result was obtained by ya - pan et al . who found that an increase in systolic bp and diastolic bp was related to a prevalence of proteinuria , however , al - saffar et al .
the likely reason might be due to a substantial reduction in renal perfusion , which leads to proteinuria . according to our study
there was a substantial statistically difference between proteinuria and patient age , which is in agreement with other studies .
this could be explained by relevant studies that found advancing age to be a risk factor for a higher prevalence of proteinuria .
therefore , the early detection of proteinuria and screening of hypertensive patients might prevent complication such as renal and cardiovascular diseases . 
 
the prevalence of proteinuria is higher in smoking hypertensive patients than in those who do not smoke .
this could be explained by the presence of endothelial dysfunction , which involves an imbalance between the contracting and relaxing substances produced by the endothelium .
for example , the plasma concentration of endothelin-14 is higher in smokers than in nonsmokers .
the present study has shown an independent relationship between proteinuria and the presence of concomitant diseases such as diabetes , congestive heart failure , and myocardial infarction .
this observation is in agreement with other studies that found a relationship between albuminuria and cardiovascular risk .
this relationship could be explained by other relevant studies in which microalbuminuria was found to indicate a generalized dysfunction of the vascular endothelium with permeability changes , which leads to a leakage of albumin through the glomerular membrane .
furthermore , the finding that the prevalence of proteinuria was higher among patients with diabetes is most likely attributable to the fact that these patients had diabetes nephropathy .
the result of our study also showed that physical activity decreased the risk of proteinuria in hypertensive patients .
this association has been previously demonstrated by reports that showing physical activity was inversely associated with microalbuminuria .
physical activity has protective effects on the vascular endothelium among patients with cardiac diseases . 
 
we found a significant association between the use of ccbs and proteinuria risk in the present study .
this can be explained by the dilating effect of ccbs on the efferent glomerular arterioles .
the present study also shows that the use of bbs is associated with proteinuria . however , kozan et al . could not find a significant association between the use of bbs and microalbuminuria risk .
the reason for this association was illustrated by other observations in which different mechanisms were identified to explain the beneficial effect of ace inhibitors and arbs on proteinuria .
second , this group of drugs can reduce the permeability of the basement membrane of the glomerulus .
both hemodynamic and non - hemodynamic effects of ace inhibitors and arbs on renal activity lead to a reduction in proteinuria among patients with hypertension .
the samples consisted of patients who were referred to an outpatient clinic for treatment . in addition , the data source was a single center and the study design was an observational analysis .
patients were not randomly selected in our study ; therefore , there might be a selection bias .
furthermore , the examination of proteinuria by using our data did not demonstrate the proportion of patients who had positive or negative results based on retesting .
moreover , concerning the study sample , the patients were selected on a convenience basis .
finally , the study only included the uzbek - turkmen ethnic group and the findings may not be generalizable to the general population .
we conclude that our results confirm the presence of a high incidence of proteinuria among hypertensive outpatients in a clinic in andkhoy , afghanistan , especially in those with a high cardiovascular risk . therefore , more frequent screening for proteinuria might be imperative for the evaluation
this project was supported in part , by the non - profit organization epidemiological and clinical research information network ( ecrin ) .
we would like to thank dr.mirwais rabi , and dr.ahmad arsalam karimi for their cooperation for this study .
 abstractproteinuria in hypertension is an early marker of renal disease and a predictor for the progression of end stage renal disease , and cardiovascular diseases . 
 this study was designed to determine the prevalence of proteinuria and its association with cardiovascular risk factors among adult hypertensive patients in afghanistan . 
 five hundred fifty - five patients with a high blood pressure recorded in an outpatient clinic in andkhoy , afghanistan from december 2014 to may 2015 , were included in this study . 
 data obtained from each patient , included demographic characteristics , body mass index , blood pressure patterns , cardiovascular history , cardiovascular risk factors , comorbidity , and current drug - therapy . 
 dipstick screening for proteinuria was performed with reagent test strips . 
 the mean age of the patients was 57.9  13.3 years , and a female predominance was observed ( n = 333 , 60% ) . 
 the prevalence of proteinuria was 67.2% . 
 the predictors of proteinuria were found to be age 65 years ( odds ratio [ or ] 1.02 , 95% confidence interval [ ci ] 1.001.04 ) , smoking ( or 1.88 , 95% ci 1.173.02 ) , heart failure ( or 2.23 , 95% ci 1.134.41 ) , and diabetes mellitus ( or 3.41 , 95% ci 1.497.81 ) . in conclusion , this study shows that proteinuria is highly prevalent among hypertensive outpatients in an outpatient clinic in andkhoy , afghanistan , especially in those with high cardiovascular risk . 
INTRODUCTION
MATERIALS AND METHODS
Subjects
Statistical analysis
RESULTS
DISCUSSION
ACKNOWLEDGEMENT
CONFLICTS OF INTEREST