Christmas, a season of joy and happiness is upon us again. Most, if not all, of us are grateful for the good health we have enjoyed this year. Some would attribute it to the yearly health checks which would alert them to potential health problems before they got too bad. Within this health check programme, some would have undergone a CT scan as recommended or have requested a CT scan to ensure completeness. Is the idea of having a ‘just in case’ CT scan a prudent move?

Researchers from the University of California conducted a retrospective cross-sectional study to assess the radiation dose associated with 11 most common types of diagnostic CT studies conducted on 1119 consecutive adult patients at 4 facilities in California between 1^st January and 30^th May 2008 (Arch Intern Med 2009; 169: 2078 – 2086). The 11 most common types of diagnostic CT scans involved the scanning of the head and neck, chest and abdomen and pelvis. These 11 types of CT scans accounted for approximately 80% of all CT scans performed. The data were then used to estimate the lifetime attributable risk for cancer associated with these scanning. The study estimated that 1 in 270 women who underwent a CT coronary angiogram at the age of 40 years will eventually develop cancer. In men, the risk is lower – 1 in 600. The estimated risk for a 40 year-old individual undergoing a routine head CT is also higher in a woman (1 in 8,100) than in a man (1 in 11,080). In 20 year-old patients, the risks are approximately double while the risks are halved in 60 year-old patients. The authors noted that a 20 year-old women who received a CT scan for suspected pulmonary embolism, a CT coronary angiography or a multi-phasic abdomen and pelvis CT could have an associated increased risk of developing cancer of 1 in 80. The associated cancer risks are of particular concern in younger female patients. The risks declined with age and are lower in men.

In the United States, the total number of CT scans performed annually has increased from approximately 3 million in 1980 to nearly 70 million in 2007. The increase was not because the population had increased exponentially or there wass a rapid increase in the number of patients falling ill. The increased CT usage was probably due to a combination of factors such as improved CT technology expanding the indications for its use and societal pressure to practice defensive medicine.

The above study is an estimation and thus could be wrong. It could under- or over-estimate the associated cancer risks from undergoing CT scanning. CT scan is important in helping doctors in their quest to diagnose and treat patients. When used judiciously it helps to save life. If used too liberally, the associated radiation exposure from CT scans will undoubtedly have an effect on one’s health. For a doctor, the concept of requesting a CT without a good clinical indication should be resisted. For the public, the temptation to request a ‘just in case’ CT scan should likewise be resisted.

Do enjoy yourself during this festive season. However, do resist the urge to over-indulge yourself. Merry Christmas!

A 9^th December Reuter article headline “Tax sugary drinks to fight the flab, says expert” caught my eye. In the article Barry Popkin, Professor of Nutrition at University of North Carolina, suggested that sugary drinks should be taxed like cigarettes in order to reduce the numbers drinking them. Depending on the country, 10 – 25% of all calories are consumed in the form of sugary or calorie-rich beverages. In USA, replacing sugary drinks with water could cut 300 – 600 calories a day from the diet of an average American. At present 1 in 3 American adults is obese which predisposes them to diabetes mellitus. In the next 25 years, the number of diabetes cases in USA is forecast to triple to 44 million and the yearly cost of caring for them will rise to $336 billion. This is just one condition related to obesity.

Nowadays, it is not uncommon to see young children drinking sugary drinks at McDonald’s. Does this predispose them to obesity? Researchers from the Pennsylvania State University studied the possible relevance of beverage intake at age 5 to adiposity and weight status across childhood and adolescence in 170 non-Hispanic white girls (Am J Clin Nutr 2009; 90: 935 – 942). These girls were assessed biennially from age 5 to 15 for beverage intake (milk, fruit juice and sweetened beverages) and energy intake. The percentage body fat, waist circumference and BMI were measured. The 5 year olds were categorized as consuming <1, ≥ 1 but < 2 or ≥ 2 servings of sweetened beverages per day. The study found that sweetened beverage intake at age 5 was positively associated with adiposity from age 5 to 15 years. The consumption of ≥ 2 servings per day was associated with a higher percentage of body fat, waist circumference and weight status at these ages. There was no association with milk or fruit juice intake.

Sugary drinks, such as Coca Cola, epitomise the American way of life and they are craved by many, young and old, throughout the world. Regular consumption brings with it the problem of increased calorie intake on top of a regular diet which contributes to the development of obesity for many. Recently, researchers from Harvard University published their forecast of the effects of obesity and smoking on life expectancy in USA. The researchers concluded that if past obesity trends continue unchecked, the negative effects of increasing BMI will overwhelm the positive effects of the decline in smoking in the population (N Engl J Med 2009; 361: 2252 -2260).

Obesity is a global health issue which is not only confined to affluent, developed societies. Taxing sugary drinks may help to tackle the issue of obesity; however, it is unlikely to solve the problem. To make a significant dent in the obesity problem, society as a whole has to demand tougher measures. For one, perhaps society should consider imposing a minimum age limit on the purchase of sugary drinks which would at least help us fight the childhood obesity epidemic. Will this fly? Most likely not.

Bird flu, swine flu, seasonal flu, winter flu and more! After the SARS incident of 2003, everyone has become more vigilant about self protection. The most recent swine flu or H1N1 incident has focused our attention on another potential communicable disease in the community. Consequently one can notice more people wearing a mask in the streets. Some would wear a simple mask, some a proper surgical face mask and not infrequently you see someone donning the N-95 mask. The N-95 mask was standard issue for all heath care workers during the SARS period. It offers the best protection provided it is fitted properly and worn properly. If the H1N1 swine flu becomes a pandemic, there won’t be enough N-95 masks for everyone. In a more practical setting, is the N-95 mask much better than a surgical mask in stopping you from picking up the flu?

Researchers from the McMaster University compared the effectiveness of the surgical mask against the N95 mask in protecting 446 nurses against influenza (JAMA 2009; 302: 1865 – 1871). These nurses were working in emergency departments, medical and paediatric units in 8 tertiary care hospitals in Ontario, Canada. They were randomly assigned to wear surgical mask (n=225) or N-95 mask (n=221). Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 mask group. There was no statistical difference in the influenza infection rate between the 2 types of mask.

If you are going to wear a mask, please make sure that you wear it properly. I have seen quite a number of people walking around with an N95 mask on their face but it was put on wrongly. In such cases the thought that you have an N95 mask on your face will certainly make you feel more secure psychologically but in reality it will not reduce your risk of getting a flu. If you are going to wear a mask, at least make sure you learn how to wear it properly.