Background: Aneurysmal subarachnoid hemorrhage (aSAH) has a mortality rate as high as 50%. The prevalence of intracranial aneurysms from various parts of India varies from 0.75 to 10.3%, with higher numbers of cases being diagnosed due to the increasing age of the population and improvements in imaging techniques. However, little is known about the attributable risk factors of aSAH in the Indian population. Methods: Using a case-control study we estimated the risk of factors such as hypertension, cigarette smoking, alcohol consumption, diabetes mellitus and family history of aSAH in a South Indian population. The population-attributable risk (PAR) of smoking, hypertension and alcohol use was estimated for the South Indian as well as for the general Indian population. Results: Our results showed that cigarette smoking (OR, 3.59; p < 0.001) and a history of hypertension (OR, 2.98; p < 0.001) were significant risk factors associated with aSAH. When patients were classified by gender, it was observed that being a smoker and having hypertension increased the risk for aSAH by nearly fourfold in men. Among women, hypertension and older age were significant risk factors. The PAR estimates indicated that smoking (OR, 3.59; 95% CI, 2.13–6.06) and hypertension (OR, 2.98; 95% CI, 1.73–5.12) are significant risk factors. Conclusions: Hypertension and smoking may be causal risk factors which might also modify the effect of genetic factors that could increase susceptibility to aSAH in the Indian population. Since these risk factors are amenable to effective modification, our findings will be useful for a gender-specific management of aSAH.

Keywords:
Intracranial aneurysm, Subarachnoid hemorrhage, risk factors, Population-attributable risk, Hypertension, Cigarette smoking
1.
Bederson JB, Awad IA, Weibers DO, Piepgras D Jr, Haley EC, Brott T, Hademenos G, Chyatte D, Rosenwasser R, Caroselli C: Recommendations for the management of patients with unruptured intracranial aneurysms: a statement for health care professionals from the Stroke Council of the American Heart Association. Stroke 2000;31:2742–2750.
2.
Linn FH, Rinkel GJ, Algra A, van Gijn J: Incidence of subarachnoid hemorrhage: role of region, year, and rate of computed tomography: a meta-analysis. Stroke 1996;27:625–629.
3.
Johnston SC, Selvin S, Gress DR: The burden, trends, and demographics of mortality from subarachnoid hemorrhage. Neurology 1998;50:1413–1418.
4.
Katati MJ, Santiago-Ramajo S, Pérez-García M, Meersmans-Sánchez Jofré M, Vilar-Lopez R, Coín-Mejias MA, Caracuel-Romero A, Arjona-Moron V: Description of quality of life and its predictors in patients with aneurysmal subarachnoid hemorrhage. Cerebrovasc Dis 2007;24:66–73.
5.
Kapoor K, Kak VK: Incidence of intracranial aneurysms in north-west Indian population. Neurol India 2003;51:22–26.
6.
Ramamurthi B: Incidence of intracranial aneurysms in India. J Neurosurg 1969;30:154–157.
7.
Teunissen LL, Rinkel GJ, Algra A, van Gijn J: Risk factors for subarachnoid hemorrhage: a systematic review. Stroke 1996;27:544–549.
8.
Feigin VL, Rinkel GJ, Lawes CM, Algra A, Bennett DA, van Gijn J, Anderson CS: Risk factors for subarachnoid hemorrhage: an updated systematic review of epidemiological studies. Stroke 2005;36:2773–2780.
9.
Feigin VL, Parag V, Lawes CM, Rodgers A, Suh I, Woodward M, Jamrozik K, Ueshima H, Asia Pacific Cohort Studies Collaboration: Smoking and elevated blood pressure are the most important risk factors for subarachnoid hemorrhage in the Asia-Pacific region: an overview of 26 cohorts involving 306,620 participants. Stroke 2005;36:1360–1365.
10.
Clarke M: Systematic review of reviews of risk factors for intracranial aneurysms. Neuroradiology 2008;50:653–664.
11.
Jindal SK, Aggarwal AN, Chaudhry K, Chhabra SK, D’Souza GA, Gupta D, Katiyar SK, Kumar R, Shah B, Vijayan VK, Asthma Epidemiology Study Group: Tobacco smoking in India: prevalence, quit-rates and respiratory morbidity. Indian J Chest Dis Allied Sci 2006;48:37–42.
12.
Mohan V, Deepa M, Farooq S, Datta M, Deepa R: Prevalence, awareness and control of hypertension in Chennai – The Chennai Urban Rural Epidemiology Study (CURES-52). J Assoc Physicians India 2007;55:326–332.
13.
Ranaweera S: Current Information on Use and Harm from Alcohol in the WHO South-East Asia Region. Alcohol Control Series No 6. New Delhi, WHO SEARO, 2006.
14.
Mohan V, Mathur P, Deepa R, Deepa M, Shukla DK, Menon GR, Anand K, Desai NG, Joshi PP, Mahanta J, Thankappan KR, Shah B: Urban rural differences in prevalence of self-reported diabetes in India – The WHO-ICMR Indian NCD risk factor surveillance. Diabetes Res Clin Pract 2008;80:159–168.
15.
Breslow NE, Day NE: Statistical Methods in Cancer Research. IARC Scientific Publications No 32. Lyon, International Agency for Research on Cancer, 1980, vol 1: The Analysis of Case-Control Studies.
16.
Nibbelink DW, Torner JC, Henderson WG: Intracranial aneurysms and subarachnoid hemorrhage – report on a randomized treatment study. 4A. Regulated bed rest. Stroke 1977;8:202–218.
17.
Harrod CG, Batjer HH, Bendok BR: Deficiencies in estrogen-mediated regulation of cerebrovascular homeostasis may contribute to an increased risk of cerebral aneurysm pathogenesis and rupture in menopausal and postmenopausal women. Med Hypotheses 2006;66:736–756.
18.
Hillbom M, Kaste M: Alcohol intoxication: a risk factor for primary subarachnoid hemorrhage. Neurology 1982;32:706–711.
19.
Adams HP Jr, Putman SF, Kassell NF, Torner JC: Prevalence of diabetes mellitus among patients with subarachnoid hemorrhage. Arch Neurol 1984;41:1033–1035.
20.
Ruigrok YM, Buskens E, Rinkel GJ: Attributable risk of common and rare determinants of subarachnoid hemorrhage. Stroke 2001;32:1173–1175.
21.
Koshy L, Easwer HV, Neetha NV, Natarajan C, Bhattacharya RN, Banerjee M: Role of endothelial nitric oxide synthase gene polymorphisms in predicting aneurismal subarachnoid hemorrhage in South Indian patients. Dis Markers 2008;24:333–339.
22.
Ohtoh T, Iwasaki Y, Suzuki H, Namba Y: The relationship of arterial hypertension to intracranial saccular aneurysms: histometric assessment of the role of hemodynamic stress in terms of arterial medial hypertrophy. Neuropathology 2007;17:181–185.
23.
Gaetani P, Tartara F, Tancioni F, Klersy C, Forlino A, Baena RR: Activity of alpha 1-antitrypsin and cigarette smoking in subarachnoid hemorrhage from ruptured aneurysm. J Neurol Sci 1996;141:33–38.
24.
Burgener E, Mooser V, Waeber B, Porchet M, Gardaz JP, Nussberger J, Brunner HR: Calcium entry blockade attenuates the acute blood pressure rise induced by cigarette smoking. J Cardiovasc Pharmacol 1988;12:126–130.
25.
Fogelholm R, Murros K: Cigarette smoking and subarachnoid haemorrhage: a population-based case-control study. J Neurol Neurosurg Psychiatry 1987;50:78–80.
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2010
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