CERTAIN ANTIHYPERTENSIVE DRUGS MAY REDUCE RISK OF PARKINSON'S DISEASE

Long-term use of calcium channel blockers may reduce the risk for Parkinson’s disease, according to a study in the February 6 online Neurology. Claudia Becker, PhD, of the Division of Clinical Pharmacology and Toxicology at University Hospital Basel in Switzerland, and colleagues included 3,637 people 40 or older who were diagnosed with Parkinson’s disease between 1994 and 2005. About 47% had ever used an antihypertensive drug prior to the start of the study (17.3% reported ACE inhibitor use, 2.5% reported angiotensin II [AT II] antagonist use, 32.1% reported β-blocker use, and 22.2% reported calcium channel blocker use).

Compared with non–Parkinson’s disease controls matched to each case for age, sex, general practice, index date, and duration of previous history in the General Practice Research Database, current use of ACE inhibitors resulted in an adjusted odds ratio (OR) for a first-time diagnosis of Parkinson’s disease of 1.00. Participants who currently used AT II antagonists or β-blockers had an increased risk for Parkinson’s disease (adjusted ORs, 1.05 and 1.19, respectively), while use of calcium channel blockers resulted in a reduced risk (adjusted OR, 0.78). Stratified by duration of treatment, the reduced risk appeared to take effect after long-term exposure to calcium channel blockers (≥ 30 prescriptions).

Dr. Becker and colleagues also noted a significantly increased risk for Parkinson’s disease for current users of one to nine β-blocker prescriptions (OR, 1.79); however, in participants with a history of cardiovascular disease, the OR for users of such prescriptions was 0.99, while the OR was 8.86 among those with no cardiovascular indication.

“We only observed a decreased OR associated with use of calcium channel blockers, but not with other hypertensives,” the researchers stated. The risk reduction was found to be greatest in those 80 or older (OR, 0.52), possibly because “with advanced age dopaminergic neurons rely increasingly on L-type CA_v1.3-calcium channels for their activity which makes them more vulnerable to neurologic damage,” they suggested.

Suggested Reading
Becker C, Jick SS, Meier CR. Use of antihypertensives and the risk of Parkinson disease. Neurology. 2008 Feb 6; [Epub ahead of print].

POSTSTROKE FUNCTIONAL STATUS AT SIX MONTHS LINKED TO LONG-TERM SURVIVAL

Among stroke patients who survived at least six months after the event, those independent in daily living survived nearly four years longer than those who were dependent, reported Karsten Bruins Slot, MD, a clinical research fellow in the Department of Internal Medicine at Ullevaal University Hospital, Oslo, and colleagues. Their findings were published in the February 16 BMJ.

The study included three cohorts of patients with ischemic stroke, for a total of 7,710 participants with a maximum poststroke follow-up of 19 years. In a combined analysis of two cohorts, “There was a significant trend of decreasing median survival with increasing Rankin score,” stated the authors. Median survival time decreased from 12.9 years in patients with a Rankin score of 0 or 1 at six months to 2.5 years for those with a six-month Rankin score of 5. With the inclusion of the third cohort, median length of survival of independent stroke patients (Rankin score, 0 to 2) was 9.7 years, versus 6.0 years for those who were dependent in daily living activities (score of 3 to 5).

Dr. Slot and colleagues reported that they were “surprised” by the poor survival rates of patients who had a Rankin score of 4 or 5. The five-year survival rate was about 45%, which the researchers said was worse than for many malignancies. The age at onset of stroke and atrial fibrillation also had a negative impact on survival. The researchers noted that the cohorts were “assembled at a time when secondary prevention in stroke survivors was much less intensive than now,” and they posited that survival would likely be better in current patients.

The results, according to the investigators, can be used to inform stroke patients about their prognosis, estimate the impact and costs of stroke, plan health care and research, and assess the cost-effectiveness of treatments. “Future studies should assess whether early interventions that reduce functional dependency at six months after onset of ischemic stroke have positive effects on subsequent long term survival, as our study suggests,” they concluded.

Suggested Reading
Slot KB, Berge E, Dorman P, et al. Impact of functional status at six months on long term survival in patients with ischaemic stroke: prospective cohort studies. BMJ. 2008;336(7640):376-379.

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