Stroke in South Asians

South Asian Stroke 

  • Over the past few decades there has been a tremendous rise in incidence and prevalence of stroke affecting South Asian population worldwide. Limited data also shows that compared to Europeans, they suffer more from haemorrhagic or lacunar strokes rather than large vessel strokes.1 South Asians have poor survival following stroke.2
  • Conflicting reports have been published on stroke rates among Indians living abroad, with most countries—Canada, for example—reporting no higher rates. However, the stroke rates among Indians in Singapore are similar to those of the Chinese, who are known to have the high rates of stroke.3  (See Table below)

Prevalence of stroke in Singapore1
  Male Female Total
Indians 4.4% 3.2% 3.6%
Chinese 4.8% 2.9% 3.8%
Malays 3.9% 2.8% 3.3%
All races 4.5% 2.9% 3.7%
  • In the UK, the incidence of stroke appears to be excessively higher in South Asians, when compared with whites, and this difference in risk continues to increase. South Asians also have a higher stroke mortality compared to Europids.4, 5 (See Figure 032) This is not surprising since heart disease and stroke share common risk factors.2
  • There is significant heterogeneity of stroke epidemiology even within the South Asian population. Stroke mortality rates for South Asians are 55% higher than whites but lower than blacks.2, 6 Bangladeshis have 200% higher rates of stroke compared to 70% for Pakistanis and 40% for Indians.7 In UK, Pakistani and African Caribbean men and Pakistani and Bangladeshi women had the highest prevalence of stroke.8
  • In the UK, the prevalence of stroke has increased to 9% in Pakistani men and 4% in Indian women.2
  • Although rates of mortality from stroke have been declining in the UK population as a whole among South Asians, the rate of decline was 10 times less than the white population.5
  • Compared to other ethnic groups, South Asian develop stroke at a younger age and yet have a higher mortality.9 South Asians with diabetes were also demonstrated to have higher long-term stroke mortality.6
  • The excess stroke mortality in South Asians is attributed to diabetes, dyslipidemia, metabolic syndrome,10, 11 17   and hypertension in contrast to whites where the main risk factors are old age and atrial fibrillation.6, 12-15
  • Elevated apolipoprotein B to A1 ratio, lipoprotein(a), homocysteine levels were found to be a significant stroke risk factor in the South Asian population.9, 16
  • A study of secular trends in risk factors in the UK showed significant increase in dyslipidemia among South Asians and blood pressure in all populations.9 These results highlights the importance of dyslipidemic management in the treatment and prevention of stroke in South Asians.

Stroke in India 

  • According to the Global Burden of Diseases Study in 1990, stroke caused 450,000 deaths in India. The number of stroke deaths was nearly a third that of heart disease. By 2020 the annual number of deaths from stroke is projected to increase to 950,000, representing a 104% increase in women and 124% increase in men. 
  • Wide variations in the prevalence of stroke in Indian have been reported. The crude prevalence rates of stroke in India varies from 52 to 842 per 100,000 for all ages.2 The prevalence rates have increased 3- to 5-fold over the last 4 decades.2
  • The estimated stroke prevalence in India (combing 9 studies) is about 0.2 percent compared to a CAD prevalence of 6% percent in urban areas and 2.7 percent in rural areas.17 In addition, the prevalence of stroke in urban India appears to be higher than that seen in rural areas.2
  • In India, there is a rural– urban gradient in stroke prevalence, which can be partly explained by adverse socioeconomic circumstances, dietary habits, and lifestyle habits that have been transformed, particularly during last 2 decades.2

Sources

1. Syed NA, Khealani BA, Ali S, et al. Ischemic stroke subtypes in Pakistan: the Aga Khan University Stroke Data Bank. J Pak Med Assoc. Dec 2003;53(12):584-588.

2. Gunarathne A, Patel JV, Gammon B, Gill PS, Hughes EA, Lip GY. Ischemic stroke in South Asians: a review of the epidemiology, pathophysiology, and ethnicity-related clinical features. Stroke. Jun 2009;40(6):e415-423.

3. Venketasubramanian N, Tan LC, Sahadevan S, et al. Prevalence of stroke among Chinese, Malay, and Indian Singaporeans: a community-based tri-racial cross-sectional survey. Stroke. Mar 2005;36(3):551-556.

4. Wild SH, McKeigue P. Cross sectional analysis of mortality by country of birth in England and Wales, 1970-92. Bmj. 1997;314(7082):705-710.

5. Balarajan R. Ethnic differences in mortality from ischaemic heart disease and cerebrovascular disease in England and Wales. Bmj. Mar 9 1991;302(6776):560-564.

6.Gunarathne A, Patel JV, Potluri R, et al. Increased 5-year mortality in the migrant South Asian stroke patients with diabetes mellitus in the United Kingdom: the West Birmingham Stroke Project. Int J Clin Pract. Feb 2008;62(2):197-201.

7. www.heartstats.org. CHD Statistics. mortality. 2010. Accessed January 25,2011.

8. Wild SH, Fischbacher C, Brock A, Griffiths C, Bhopal R. Mortality from all causes and circulatory disease by country of birth in England and Wales 2001-2003. J Public Health (Oxf). Jun 2007;29(2):191-198.

9. Gunarathne A, Patel JV, Potluri R, Gill PS, Hughes EA, Lip GY. Secular trends in the cardiovascular risk profile and mortality of stroke admissions in an inner city, multiethnic population in the United Kingdom (1997-2005). J Hum Hypertens. Jan 2008;22(1):18-23.

10. Deleu D, Hamad AA, Kamram S, El Siddig A, Al Hail H, Hamdy SM. Ethnic variations in risk factor profile, pattern and recurrence of non-cardioembolic ischemic stroke. Arch Med Res. Jul 2006;37(5):655-662.

11. Kain K, Catto AJ, Grant PJ. Clustering of thrombotic factors with insulin resistance in South Asian patients with ischaemic stroke. Thromb Haemost. Dec 2002;88(6):950-953.

12. Jafar TH. Blood pressure, diabetes, and increased dietary salt associated with stroke–results from a community-based study in Pakistan. J Hum Hypertens. Jan 2006;20(1):83-85.

13. Gupta R, Joshi P, Mohan V, Reddy KS, Yusuf S. Epidemiology and causation of coronary heart disease and stroke in India. Heart. Jan 2008;94(1):16-26.

14. Moussouttas M, Aguilar L, Fuentes K, et al. Cerebrovascular disease among patients from the Indian subcontinent. Neurology. Sep 12 2006;67(5):894-896.

15. Kaul S, Sunitha P, Suvarna A, Meena AK, Uma M, Reddy JM. Subtypes of Ischemic Stroke in a Metropolitan City of South India (One year data from a hospital based stroke registry). Neurol India. Dec 2002;50 Suppl:S8-S14.

16. Sharobeem KM, Patel JV, Ritch AE, Lip GY, Gill PS, Hughes EA. Elevated lipoprotein (a) and apolipoprotein B to AI ratio in South Asian patients with ischaemic stroke. Int J Clin Pract. Nov 2007;61(11):1824-1828.

17. Mahal A, Karan A, Engelgau MM. The Economic Implications of Non-Communicable Disease for India: avaible at WWW.World Bank/documents and reports. Accessed  November 1, 2010;2010.

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