Friday, April 29, 2011

Olmesartan:Safety update report by FDA

After reviewing the results of the ROADMAP and ORIENT trials (1), US FDA has determined that the benefits of Benicar (Olmesartan) continue to outweigh its potential risks when used for the treatment of patients with high blood pressure according to the drug label.(2)

Benicar (Olmesartan) is not recommended as a treatment to delay or prevent protein in the urine (microalbuminuria) in diabetic patients.

In November, 2011, US FDA (3) had mentioned that it is evaluating data from two clinical trials in which patients with type 2 diabetes taking the blood pressure medication, Benicar (olmesartan) had a higher rate of death from a cardiovascular cause compared to patients taking a placebo.

ROADMAP and ORIENT are both long-term clinical trials. In both trials, patients with type 2 diabetes were given either Benicar or placebo to determine if treatment with Benicar would slow the progression of kidney disease. An unexpected finding observed in both trials was a greater number of deaths from a cardiovascular cause (heart attack, sudden death, or stroke) in the Benicar-treated patients compared to placebo.
 Benicar (olmesartan) is in the class of drugs called angiotensin II receptor blockers (ARBs). These drugs and a closely related group of drugs called angiotensin-converting enzyme inhibitors (ACEIs) have been evaluated in many studies involving thousands of patients at high-risk for cardiovascular events, such as patients who had a previous heart attack or had heart failure. No increased risk of cardiovascular-related death has been reported in these trials and, in fact, some of these studies indicate ARBs and ACEIs are useful as treatments for certain patients at high-risk for cardiovascular events.
(1)  Haller H, Ito S, Izzo JL, et al. Olmesartan for the delay or prevention of microalbuminuria in Type 2 Diabetes. N Engl J Med 2011;364:907-17

Sunday, April 24, 2011

Screen time has a potential adverse influence on retinal microvascular structure.

The magnitude of arteriolar narrowing associated with each hour daily of TV viewing is similar to that associated with a 10-mm Hg increase in systolic blood pressure in children.

A study mentioning the influence of physical activity and screen time on the retinal microvasculature in young children will be published in May issue of Arterioscler Thromb Vasc Biol. 2011

Gopinath B and colleagues of University of Sydney, Australia have investigated the associations among physical activity (outdoor and indoor sporting activities), sedentary behaviors (including screen time, television [TV] viewing, and computer and videogame usage), and retinal microvascular caliber in schoolchildren.

Six-year-old students (1765/2238) from a random cluster sample of 34 Sydney schools were examined. Parents completed questionnaires about physical and sedentary activities. Retinal images were taken, and retinal vessel caliber was quantified.
After adjusting for age, sex, ethnicity, eye color, axial length, body mass index, birth weight, and mean arterial blood pressure, children who spent more time in outdoor sporting activities (in the highest tertile of activity) had 2.2 μm (95% CI 0.65 to 3.71) wider mean retinal arteriolar caliber than those in the lowest tertile (P(trend)=0.004). Increasing quartiles of time spent watching TV were associated with narrower mean retinal arteriolar caliber ≈2.3 μm (95% CI 0.73 to 3.92), P(trend)=0.003.
The authors concluded that the data suggests that physical activity could have a beneficial influence, whereas screen time has a potential adverse influence on retinal microvascular structure.

Calcium supplements and cardiovascular events

Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, according  to a study published in April issue of BMJ (1). 
Bolland BJ and colleagues have reanalysed of WHI CaD Study limited access dataset with incorporation of meta-analysis eight other studies have. WHI CaD Study, a seven year, randomized, placebo controlled trial of calcium and vitamin D (1g calcium and 400 IU vitamin D daily) in 36 282 community dwelling postmenopausal women.
Main outcome measure: Incidence of four cardiovascular events and their combinations (myocardial infarction, coronary revascularisation, death from coronary heart disease, and stroke) assessed with patient-level data and trial-level data.
The results of WHI CaD Study show that there is an interaction between personal use of calcium supplements and allocated calcium and vitamin D for cardiovascular events. In the 16 718 women (46%) who were not taking personal calcium supplements at randomization the hazard ratios for cardiovascular events with calcium and vitamin D ranged from 1.13 to 1.22 (P=0.05 for clinical myocardial infarction or stroke, P=0.04 for clinical myocardial infarction or revascularisation), whereas in the women taking personal calcium supplements cardiovascular risk did not alter with allocation to calcium and vitamin D.
In meta-analyses of three placebo controlled trials, calcium and vitamin D increased the risk of myocardial infarction (relative risk 1.21 (P=0.04), stroke (P=0.05), and the composite of myocardial infarction or stroke (P=0.02).
Calcium or calcium and vitamin D increased the risk of myocardial infarction (P=0.004) and the composite of myocardial infarction or stroke (P=0.009).
The authors concluded that Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction. This finding was obscured in the WHI CaD Study by the widespread use of personal calcium supplements.