Archive for April, 2011

Calcium Supplements May Not Be That Safe After All….

April 25, 2011

It has always been my practice to make sure women take their daily calcium supplements to prevent osteoporosis.  It is my contention that by building bone the right way and preventing a fracture is very important health issue.  It is recommended by diffirent medical societies that calcium supplements be given between 1000- 1200 mg per day. 

Now comes a new study showing proofs that calcium supplements may not be that safe after all.  A study published in BMJ in JUly 2010 with a reanalysis done in 2011 showed that calcium supplementation should be reviewed due to inherent harm.

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Abstract

OBJECTIVE:

To investigate whether calcium supplements increase the risk of cardiovascular events.

DESIGN:

Patient level and trial level meta-analyses.

DATA SOURCES:

Medline, Embase, and Cochrane Central Register of Controlled Trials (1966-March 2010), reference lists of meta-analyses of calcium supplements, and two clinical trial registries. Initial searches were carried out in November 2007, with electronic database searches repeated in March 2010.

STUDY SELECTION:

Eligible studies were randomised, placebo controlled trials of calcium supplements (>or=500 mg/day), with 100 or more participants of mean age more than 40 years and study duration more than one year. The lead authors of eligible trials supplied data. Cardiovascular outcomes were obtained from self reports, hospital admissions, and death certificates.

RESULTS:

15 trials were eligible for inclusion, five with patient level data (8151 participants, median follow-up 3.6 years, interquartile range 2.7-4.3 years) and 11 with trial level data (11 921 participants, mean duration 4.0 years). In the five studies contributing patient level data, 143 people allocated to calcium had a myocardial infarction compared with 111 allocated to placebo (hazard ratio 1.31, 95% confidence interval 1.02 to 1.67, P=0.035). Non-significant increases occurred in the incidence of stroke (1.20, 0.96 to 1.50, P=0.11), the composite end point of myocardial infarction, stroke, or sudden death (1.18, 1.00 to 1.39, P=0.057), and death (1.09, 0.96 to 1.23, P=0.18). The meta-analysis of trial level data showed similar results: 296 people had a myocardial infarction (166 allocated to calcium, 130 to placebo), with an increased incidence of myocardial infarction in those allocated to calcium (pooled relative risk 1.27, 95% confidence interval 1.01 to 1.59, P=0.038).

CONCLUSIONS:

Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction. As calcium supplements are widely used these modest increases in risk of cardiovascular disease might translate into a large burden of disease in the population. A reassessment of the role of calcium supplements in the management of osteoporosis is warranted.

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The reanalysis of this study done recently and published in the same journal showed that the risk of MI is actualy MODEST at best around 20% for MI and 30% for stroke BUT… considering the huge number of women doctors have been recommending to take calcium supplements… justify a further close look at this practice as this will have enormous impact on health care risk.

For the past year…I have not been recommending calcium supplements to my patients especially my diabetic hypertensive patients.  I make sure that my dietitian supplements their diet with enough calcium sources from food and milk.  If need be, those patients who cant take enough from food are the ones given the supplements but this number is becoming less each day.

If you are taking calcium supplements on your own , my recommendation is to stop.  If you are taking the supplements as part of your osteoporosis program then talk to your doctor first before stopping.

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The Health Issue of Cell Phone Use

April 13, 2011

Ive long been cautious of letting my kids use cell phones even for a short period of time.  Their brains are still developing and need the best nurturing they can get and if we can limit inflicting harm to avoid long term defects would be ideal.

A novel study recently published in JAMA tells us that cell phone use was shown to affect brain activity:

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Context The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear.

Objective To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity.

Design, Setting, and Participants Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with (18F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes (“on” condition) and once with both cell phones deactivated (“off” condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm3) and P < .05 (corrected for multiple comparisons) were considered significant.

Main Outcome Measure Brain glucose metabolism computed as absolute metabolism (μmol/100 g per minute) and as normalized metabolism (region/whole brain).

Results Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 μmol/100 g per minute; mean difference, 2.4 [95% confidence interval, 0.67-4.2]; P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001).

Conclusions In healthy participants and compared with no exposure, 50-minute cell phone exposure was associated with increased brain glucose metabolism in the region closest to the antenna. This finding is of unknown clinical significance.

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Analysis of the data showed that the human brain is indeed sensitive to the effects of radiofrequency from acute cell phone use.  And that the area closest to the antennae revealed the highest brain activity.  Whether this disruption in brain activity has long term consequences is still unknown.

Take Home message?

Use the phone for texting…and use it sparingly for calling.

Restricting use of cell phones in kids will continue to be my recommendation until better studies will show that indeed its use is safe for kids until age 18.  Too late? well better be safe than sorry….

But hopefully soon before my son reaches tha age where cell phones are a must..we have better studies showing its safety…Cross my fingers!!!

Tylenol and Hypertension: Is There A Link?

April 13, 2011

It has always been my notion that tylenol is the safest of all pain relievers.  Most patinets of mine are advised to take acetaminophen instead of NSAIDS especially if they have arthritis  and have concomitant heart disease or kidney problem.  We all know about the Viox controversy when it was pulled out due to cardiovascular safety.

Now comes a recent report from the Harvard Health Beat regarding a Swiss study that showed taking acetaminophen better known for the brand Tylenol, can actually cause an elevation of Blood pressure.

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The researchers asked 33 men and women with one or more of these problems to take either 1,000 milligrams (mg) of acetaminophen or an identical placebo three times a day for two weeks. Then, after a two-week break, each volunteer took the other treatment. The amount of acetaminophen used in the study is a standard daily dose for pain.

When the participants took acetaminophen, average systolic blood pressure (the top number of a blood pressure reading) increased from 122.4 to 125.3, while the average diastolic pressure (the bottom number) increased from 73.2 to 75.4. Blood pressure stayed steady when participants took the placebo. These increases aren’t large. But they indicate that acetaminophen, like NSAIDs, somehow affects the cardiovascular system.

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Acetaminophen indeed is a safe alternative to the pain killers known as NSAIDs becuase it is safe to the stomach and avoid gastric irritation. 

It is also a better alternative especially to patients taking anticoagulants or drugs to prevent blood clots because it does not interfere with their actions nor further increase bleeding tendencies.

However… people should be extra careful with this new information and therefore should not take acetaminophen lightly.  Meaning, one should also be cautious in taking acetaminophen with a slight onset of headache especially among patients with concomitant cardiovascular disease. 

No matter how safe a drug is perceived to be… along the way comes an alternative that will always be safer… or the other way around.  It is best that we be kept informed because we may be taking drugs that may instead cause harm than good. It is therefore always worth having a periodic visits to your family doctor.