| Abstract|| |
Kuwait is a small country located on the northeastern part of the Arabian Peninsula. The most recent data on hypertension show: (a) a prevalence rate of 26.3%, (b) awareness of the disorder in only 23% of affected persons, (c) mild to moderate hypertension in 86% of subjects, (d) increased proportion of hypertensive patients at older age, (e) high prevalence in diabetics at age > 35 years and (f) high association with obesity. Most patients still use beta-blockers with a recent surge in calcium channel-blockers (except for immediaterelease nifedipine) and angiotensin converting enzyme inhibitors. Hypertension was responsible for 935 hospital admissions in 1997. Its related co-morbid conditions such as ischemic heart disease, cerebrovascular accidents, congestive heart failure and chronic renal failure were responsible for 4111, 791, 690 and 978, hospital admissions, respectively, during the same year. Hypertension is the fourth common cause of end-stage renal disease. The most disturbing observation is the lack of disease awareness and the persistently high mortality rate of the disease and its co-morbid conditions. Efforts should be directed towards increase of awareness of this important risk factor for cardiovascular disease.
Keywords: Cerebrovascular accidents, Coronary artery disease, Hypertension, Kuwait, Obesity, Renal failure.
|How to cite this article:|
El-Reshaid K, Al-Owaish R, Diab A. Hypertension in Kuwait: The Past, Present and Future. Saudi J Kidney Dis Transpl 1999;10:357-64
|How to cite this URL:|
El-Reshaid K, Al-Owaish R, Diab A. Hypertension in Kuwait: The Past, Present and Future. Saudi J Kidney Dis Transpl [serial online] 1999 [cited 2020 Aug 4];10:357-64. Available from: http://www.sjkdt.org/text.asp?1999/10/3/357/37244
| Introduction|| |
Hypertension is the most common medical problem seen by physicians, accounting for more office visits, prescriptions and work absenteeism than any other disease.  It is considered one of the major risk factors for coronary artery disease, cerebrovascular accidents, chronic renal failure and congestive heart failure.
This belief was based on the decline in age-adjusted mortality for stroke (59%) and coronary artery disease (53%) from 1972 to 1994 in USA which was attributed to the improvement in awareness and control of blood pressure through the efforts of the National High Blood Pressure Educational Program.  This program was established in USA in 1972 with a mission of increasing awareness, prevention, treatment and control of hypertension. Their periodic surveys showed increased awareness of hypertension from 51 % in 1976 to 73% in 1980, treatment from 31% to 55% and normalization of blood pressure (below 140/90 mmHg) from 10%to29%. 
Moreover, prospective and controlled trials supporting the benefit of normalization of high blood pressure were available in the field of: (a) stroke (6 trials)  (b) cardiovascular mortality in the elderly (5 trials)  and (c) cardiovascular mortality with diuretics and beta blockers in adults. 
Outside the USA, information on hypertension is limited in most nations, including the Arabic countries. Multiple factors contributed negatively to such phenomenon such as the silent nature of hypertension and the limited resources to conduct nationwide studies.
In this report, we analyze data collected from different departments in Kuwait, to highlight the epidemiological profile of hypertension in Kuwaiti nationals, the trends of therapy, and morbidity and mortality.
| Epidemiology of Hypertension in Kuwaiti Nationals|| |
Kuwait is a small country located on the northeastern part of the Arabian Peninsula and has an area of 17818 km 2 (6960 sq. miles). It is a cosmopolitan country with a large expatriate population, accounting for nearly half of the total population.  Since the latter group consists mainly of a heterogeneous group of manual laborers, only prevalence rates in Kuwaiti nationals are expected to represent a meaningful epidemiological finding. Hypertension was studied in a nationwide survey by ElDesouky et al.  Another survey is being conducted by Al-Owaish et al.
The first report  studied the pattern of blood pressure in adult subjects attending polyclinics in Kuwait in 1980. The total number of subjects included in the study was 16,046 individuals of whom 28% were Kuwaiti nationals.
This study showed that the overall (all inhabitants of the country) prevalence rate of hypertension was 10.3% (8.3% in males and 12.9% in females). In Kuwaiti nationals, the prevalence rate was 8% in males and 9% in females. The study also showed that the prevalence rates of systolic and diastolic hypertension increased (a) with advancing age, (b) at higher body weight, (c) with higher level of education, (d) in married males and (e) with increased family size.
Previous knowledge of hypertension was lacking in 73.6% of hypertensive men and 53.4% of hypertensive women. Among hypertensive males, 70.4% were not laking any medications and only 14.4% were taking antihypertensive therapy on regular basis, while the respective figures in females were 52.7% and 24.5%. Unfortunately, the study did not report separate analysis of data on Kuwaiti nationals.
The second study is an on-going study, conducted by Al-Owaish et al. to update the current status of hypertension in Kuwait. The investigators are using mobile units set at different public places, such as Parks, seaside, shopping centers and different university complexes. They measure blood pressure in volunteers (adults, 18 years and above) at these sites. Participants are requested to answer a specific questionnaire that includes details on some risk factors associated with cardiovascular diseases. This publicly advertised health program is generating useful data and we will review some preliminary results in our present report. Over the past 2 years, 5233 adults were screened; 2836 were native Kuwaitis. A summary of the results is shown in [Table - 1]. Hypertensive and non-hypertensive subjects were compared according to three age groups, sex and certain cardiovascular risk features. The results show that 745 (26.3%) of 2836 Kuwaiti had hypertension. The prevalence rate was 28.3% in males and 22.9% in females. Awareness of hypertension was present in 23% of hypertensive patients (24% in females and 23% in males). When data were analyzed according to age groups (18-34, 35-59 and 60+ years), the proportion of hypertensive patients was higher in the older age groups (males: 17.5%, 35% and 44.4% and females: 11.1 %, 33.2% and 58.3%, respectively).
Three more findings were important. First, 86% of males and 86% of females had diastolic blood pressure values of 109 mmHg or below (mild to moderate hypertension). Second, a higher proportion of hypertension existed in diabetics only after the age of 3 5 years. Third, no significant association was found between the presence of hypertension and any of the following variables: (a) family history of hypertension, (b) previous history of cardiovascular disease and (c) smoking. However, there was an evident association with obesity. Most patients, in Kuwait, had mild to moderate (stage I and II) hypertension, which is similar to that reported from the USA.  It is probable that the exact percentage of "mild hypertension" might have been lower if true sampling was done rather than being limited by the methodology of the study, which limited itself to screening mobile and voluntary subjects. The finding of a tendency for higher blood pressure with age and the close association of essential hypertension with type-II diabetes mellitus and obesity is similar to the experience in the USA.  However, the weak association with family history of hypertension and associated cardiovascular disease was unexpected. The high prevalence of obesity among Kuwaiti nationals and its stronger association with hypertension may have been a confounding factor altering the familial aggregation of the disease. In a similar fashion, high prevalence of obesity and cigarette smoking (23%) among Kuwaiti nationals might have affected the results of morbidity.  The latter two hypothesis are intriguing and can be answered if multi-variant analysis is applied to a larger sample size in future.
Caution should be exercised in interpreting the present results of this ongoing study, since data are being collected from voluntary and mobile subjects. It may be different if bed-ridden or frequently hospitalized patients are included.
| Lessons from the pattern of antihypertensive drug usage|| |
In order to evaluate the trends in antihypertensive therapy, we studied the yearly consumption of drugs by the dispensing of antihypertensives from central medical stores to different hospitals in three different years at five-year intervals. To estimate the number of patients treated with a certain drug, the yearly consumption of the drug was divided by the daily frequency of its usage and then by 365 (days of a year)
[Table - 2] shows the results of this survey. The use of diuretics and beta-blockers as antihypertensive drugs did not change over the study years. The use of the former may have been due to its constant recommendation by most experts as the first line of antihypertensive therapy (with or without beta blockers). Diuretics were used in smaller doses than those used in Framing-hams study, which was considered responsible for the deleterious effects on blood sugar, lipids and electrolytes.  Diuretics are still used as adjuvants to other antihypertensive medications to prevent secondary salt and water retention, since almost all antihypertensives cause salt retention.  On the other hand, beta-blockers are favored by most physicians because of their positive cardioprotective effects,  though they have common adverse effects on libido and reduced penile erection. 
In general, the use of direct vasodilators and centrally acting adrenergic drugs is declining except alfa-methyldopa. This may be due to its safe profile in treating hypertension during pregnancy and/or as the fourth antihypertensive drug for resistant hypertension after diuretics, betablockers and vasodilators.
Of the direct vasodilators, hydralazine is still used by most pediatricians and minoxidil by nephrologists for severe hypertension but in doses not exceeding 5 mg/day to avoid the significant side-effects.
Peripheral adrenergic blocking agents such as guanithidine are no more used in Kuwait because of their unacceptable level of side effects. Alpha-1-receptor blockers, though the least used anti-hypertensives in Kuwait, maintained a constant level of consumption over the years. This may be due to their beneficial effects on lipids, sugar and symptoms of benign prostatic hyperplasia in the elderly.
The angiotensin-converting enzyme inhibitors (ACEI) showed a dramatic surge in their usage in the 90's. This may be related to their beneficial effects on the heart, vasculature and kidneys especially in patients with heart failure,  myocardial infarction,  diabetes mellitus  and renal impairment.  Interestingly, in the year (87-88), only captopril was available and to a lesser extent enalapril. In the year (97-98), lisinopril was the most ACEI used. The use of captopril did not change, yet enalapril use declined mostly due to its high cost.
The use of the recently introduced angiotensin II receptor blockers was limited primarily to patients in whom ACEI were indicated but had cough as side-effect.
Calcium channel blockers continue to enjoy a wide-acceptance rate due to their potent antihypertensive effects. However, the use of immediate-release nifedipine declined from 3092 patients in the year 87-88 to 1783 patients in the year 97-98, possibly due to negative reports on its association with higher mortality in hypertensive emergencies  and in post-myocardial infarction patients. 
| Morbidity and Mortality|| |
As shown in [Table - 3], hypertension and other cardiovascular diseases constitute a major "bulk" of governmental expenditure on health.  Despite their relatively small number, cardiovascular diseases are associated with more frequent visits to outpatient clinics, use of expensive therapeutics, intensive care admissions, longer "average length of stay" in hospital and work-absenteeism in comparison to other admissions such as natural delivery, infectious diarrhea, tonsillitis and asthma.
Hypertension is the fourth cause of end-stage renal disease in Kuwaiti nationals after diabetes, chronic glomerulonephritis and chronic tubulointerstitial disease, [Table - 4]. It contributed 6.3% of the causes of renal failure in the 363 patients accepted on renal replacement therapy in the past three years. Interestingly, there has been no significant decline in prevalence of hypertension since the late 80's. Furthermore, there was no further decline in the rate of deaths attributed to cardiovascular diseases or hypertension in 1997 as compared to 1989, [Table - 5].
| Conclusion|| |
In the past few years, there was no significant improvement in control of cardiovascular diseases in Kuwait. Our data show a persistently low level of hypertension awareness and treatment since 1980. Unfortunately, this occurs in a country with adequate "public media", freeof-cost health facilities and access to the "best cardiovascular drugs". Moreover, we observe a high prevalence of obesity and cigarette smoking. These factors have been shown to affect morbidity and mortality and should be addressed in any program with an intention to treat hypertension.
Finally, we have to acknowledge the limitations of results of our analysis, being approximate figures of data collected by different departments and for different purposes. There are no solid data or a well designed study to address "the exact incidence, prevalence and true benefits of current antihypertensive therapy in our area". We hope it can be done in future.
| References|| |
|1.||Houston MC. Hypertension strategies for the rapeutic intervention and prevention of end-organ damage. Prim Care 1991; 18:713-53. |
|2.||National Heart, Lung and Blood institute staff. Calculated data. Cutler J Principal Investigator. Bethesda Md; National Heart, Lung and Blood Institute; January 1997 [unpublished data]. |
|3.||Burt VL, Cutler JA, Higgins M. Trends in the prevalence, awareness, treatment, and control of hypertension in the adult US population. Data from the health examination survey, 1960 to 1991. Hypertension |
|4.||Lever AF, Ramsay LE. Treatment of hypertension in the elderly.J Hypertens1995;13:571-9. |
|5.||Mac Mahon S, Rodgers A. The effects of blood pressure reduction in older patients: an overview of five randomized controlled trials in elderly hypertensives. Clin Exp Hypertens 1993; 15:967-78. |
|6.||Psaty BM, Smith NL, Siscovick DS. et al. Health outcomes associated with antihypertensive therapies used as firstline agents. A systematic review and meta-analysis. JAMA 1997;277:739-45. |
|7.||Annual statistical analysis, Central statistical office, Ministry of Planning, Kuwait. |
|8.||Desouky M. Blood pressure level and epidemiology of hypertension in Kuwait. Council of Ministers, Secretariat General, Department of Social Research, Kuwait1980. |
|9.||Houston MC, Meador BP, Schipani LM. Total cost of antihypertensive therapy. In: Handbook of antihypertensive therapy 8thedition, Hanley & Belfus, Philadelphiapage 2. |
|10.||The 6th report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med 1997; 157:2413-46. |
|11.||WHO/EMRO. Health statistics and trends report 1993. |
|12.||Kannel WB. Some lessons in cardiovascular epidemiology from Framingham. Am J Cardiol 1976;37:269-82. |
|13.||Diuretics-past, present and future prospects in cardiovascular disease: Proceedings of a seminar. Eur Heart J 1992;13(Suppl) |
|14.||Five-year findings of the hypertension detection and follow-up program. I. Reduction in mortality of persons with high blood pressure, including mild hypertension. Hypertension Detection and Follow-up Program Cooperative Group. JAMA 1979:242:2562-71. |
|15.||Steiner SS, Friedhoff AJ, Wilson BL, Wecker JR, Santo JP. Antihypertensive therapy and quality of life: a comparison of atenolol, captopril, enalpril and propra-nolol. J Hum Hypertens 1990;4:217-25. |
|16.||Gottdiener JS, Reda DJ, Massie BM, Materson BJ, Williams DW, Anderson RJ. Effect of single-drug therapy on reduction of left ventricular mass in mild to moderate hypertension: comparison of six antihypertensive agents: The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents. Circulation 1997; 95:2007-14. |
|17.||Hennekens CH, Albert CM, Godfried SL, Gaziano JM, Buring JE. Adjunctive drug therapy of acute myocardial infarctionevidence from clinical trials. N Engl J Med 1996;335:1660-7. |
|18.||Lewis EJ, Hunsicker LG, Bain RP, Rohde RD. The effect of angiotensinconverting-enzyme inhibition on diabetic nephropathy. The collaborative study group. N Engl J Med 1993;329:1456-62. |
|19.||Giatras I, Lau J, Levey AS. Effect of angiotensin converting enzyme inhibitors on the progression of nondiabetic renal disease: a meta-analysis of randomized trials. Angiotensin Converting Enzyme Inhibition and Progressive Renal Disease Study Group. Ann Intern Med 1997; 127: 337-45. |
|20.||Grossman E, Messerli FH, Grodzicki T, Kowey P. Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies? JAMA 1996;276:1328-31. |
|21.||Furberg CD, Psaty BM, Meyer JV. Nifedipine. Dose-related increase in mortality in patients with coronary heart disease. Circulation 1995 ;92:1326-31. |
|22.||Health & vital statistics, Department of statistics & medical records, Ministry of Health, Kuwait, Edition xxxiv, 1997. |
|23.||El-Reshaid K, Johny KV, Sugathan TN, Hakim A, Georgous M, Nampoory MR. End-stage renal disease and renal replacement therapy in Kuwait epidemiological profile over the past 4 1/2 years. Nephrol Dial Transplant 1994;9:532-8. |
Department of Medicine, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5]