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Healthcare Market Review

Will continued improvements in mortality founder on the ‘icebergs’ of obesity and diabetes?

Daniel Ryan explores the issues.

We have seen dramatic reductions in mortality rates at all ages during the 20th century through a combination of better hygiene, better public health and preventative measures, confounded by changes in the prevalence of smoking over that period. As we move through the early stages of the 21st century, many demand further ‘miracles’ from traditional and complementary medicine, with much focus upon developments in areas such as stem cell research and imaging technology. Perhaps we do not fully appreciate that our own actions are moving us in the opposite direction.

On 11 February 2004, the Royal College of Physicians, Faculty of Public Health and the Royal College of Paediatrics and Child Health, issued a report Reducing and Preventing Obesity that called for an immediate response to the rapid emergence of an epidemic in obesity, focusing their attention on young adults and children.

Obesity is defined as having a Body Mass Index, or BMI, of more than 30. The BMI is calculated as your mass in kilograms divided by your height, in metres, squared. Between 1980 and 2001, the proportion of the UK population between ages 16 and 64 with a BMI of 30 or more increased from 6% to 21% for males and 8% to 24% for females. As a society, we may not understand the significance of these figures, perhaps assuming that medical science will be able to save us from ourselves.

The increase in obesity is believed to be due to a combination of factors including increased prevalence of sedentary lifestyles, genetic susceptibility to obesity and high-calorie diet. Obesity has both direct and indirect effects on cardiovascular function. Total blood volume increases, which places a greater strain on the heart, leading initially to increased heart size and then the possibility of either heart failure or myocardial infarction as noted in the continuing Framingham Heart Study¹.

Truncal obesity, where fat is deposited around the abdomen is a particularly dangerous condition as this leads to increased levels of free fatty acids being delivered to the liver. This disrupts the normal homeostatic balance between glucose and insulin in the body and leads to insulin resistance as cells deliberately become less sensitive to the high levels of circulating insulin. This is type 2 diabetes.

The risk of type 2 diabetes increases alarmingly with progressive obesity. Based on a cohort study of nurses², an individual with a BMI of 25 had five times the risk of type 2 diabetes compared to one with a BMI of 21. This multiple increased to 28 for a BMI of 30 and 93 for a BMI of 35. It should, therefore, not come as a surprise that we are seeing dramatic increases in type 2 diabetes. At present, 3% of the UK adult population is diagnosed with type 2 diabetes, but it is suspected that there are many other cases of undiagnosed type 2 diabetes. It is expected that there will be three million cases of diagnosed and undiagnosed type 2 diabetes by 2010.

The risk of high blood pressure is significantly greater in those with diabetes. There is an increased probability of peripheral vascular problems as there is increased prevalence of blood coagulation factors and a reduced ability to remove developing blood clots. Metabolic syndrome X has been identified as an immediate precursor to type 2 diabetes and is identified with truncal obesity, insulin resistance, hypertension and high levels of low density lipoproteins. These latter molecules have a high proportion of cholesterol and are strongly implicated in atheroma formation, which can lead on to myocardial infarction and stroke.

If this all sounds rather apocalyptic for society in general, it should. In considering an insured population, there is an inverse link between the prevalence of obesity and socio-economic class. The Health Survey for England in 1998³ showed that the prevalence of obesity amongst women was 28% for social class V as opposed to 15% for social class I. The corresponding values for men were 18% and 12% respectively. Figure 1 demonstrates the differences by socio-economic class. Figure 2 shows the prevalence of obesity has continued to increase since 1998, especially for men.

However, before insurers draw too much comfort from these findings, assumed incidence rates for cardiovascular claims on critical illness policies would most likely have been based on the lower risk of cardiovascular disease amongst higher socio-economic classes. The upward trend in obesity over time is expected to be at a slower rate for the higher socio-economic classes, but future incidence rates might still need to allow for greater deterioration than is currently assumed, and insurers would be exposed on existing business.

People are starting to comprehend the risks associated with diabetes and obesity and, particularly in the US, there is no shortage of quick fix answers. The reality is that the probabilities of cardiovascular disease and of type 2 diabetes can be significantly lessened, in many cases, by changes in lifestyle to maintain normal weight and to increase physical activity. For others, there are effective medications to help control blood glucose, blood pressure and cholesterol.

We have now heard the bell clearly signalling the approach of these ‘twin icebergs’. Those working in the insurance industry need to watch carefully to see if the warnings are heeded, as they may need to consider strategic actions in order to ensure the financial viability of existing business portfolios, and to develop profitable health and protection customer propositions appropriate for the future.

References

1.	Obesity and the risk of heart failure, New England Journal of Medicine (2002), Volume 347, pages 305-313
2.	Weight Gain as a Risk Factor for Clinical Diabetes Mellitus in Women, Annals of Internal Medicine (1995), Volume 122, Issue 7, pages 481-6
3.	Health Survey for England, Cardiovascular Disease (1998)