Class 1: ≤ 34.99
MI = body mass index; CDC = Centers for Disease Control and Prevention; SD = standard deviation of the optimum weight-for-height; WH = weight-for-height; WHO = World Health Organization; Z = Z-score.
In the USA, a 2005 estimation indicated that obese men are thought to incur an additional US $1152 annually per person in medical spending, while obese women incur over double that. The authors estimate that around US $190 billion per year, approximately 21% of US health care expenditure, is due to treating obesity and obesity-related conditions14. In Europe, a 2008 review of 13 studies in 10 western European countries estimated the obesity-related health care burden had a relatively conservative upper limit of €10.4 billion annually15,16.
1.1.2 Diabetes mellitus
Diabetes was first described in the Ebers Papyrus in 1500 BC, when it was called ‘too great emptying of the urine’. At the time, physicians from India observed that the urine from people with diabetes attracted ants and flies, calling it ‘honey urine’. In 1776, the British physiologist Matthew Dobson first described that the sweet-tasting substance in the urine was sugar. However, it was only in the nineteenth century that glycosuria became an accepted diagnostic criterion for diabetes, after Michel Eugène Chevreul observed in 1815 that the sugar found in urine was glucose and after Hermann Von Fehling developed a quantitative test for glucose in urine in 184817. Between 1893 and 1909, several researchers, including Paul Langerhans, observed that insulin deficiency was the factor responsible for the development of diabetes. Prior to its isolation and clinical use in 1922 by Frederick Banting and Charles Best, the only known treatment for diabetes was starvation diets, with not uncommonly death from starvation in some patients with diabetes T2DM17. Regarding oral hypoglycaemic agents, in 1918, C. K. Watanabe observed that guanidine caused hypoglycaemia17. Ten years later, biguanidine, a guanidine-modified molecule, was introduced for treatment of diabetes in Europe17. In 1949, Becton, Dickinson and Company began the production of a standardised insulin syringe designed and approved by the American Diabetes Association (ADA). The standardised syringe reduced dosing errors and the associated episodes of hyperglycaemia and hypoglycaemia.
Diabetes impacts more than 415 million people worldwide and two thirds of people with diabetes die of heart disease and stroke18. In addition, the risk for cardiovascular disease mortality is two to four times higher in people with diabetes than in people who do not have diabetes7. Diabetes is a disease that rarely occurs alone. When it is combined with abdominal obesity, high cholesterol and/or high blood pressure, it becomes a cluster of the highest risk factors of heart attack. The combination of these diseases is termed metabolic syndrome (MS), also known as insulin-resistance syndrome or cardiometabolic syndrome. According to the most recent guidelines issued in 2009 by the International Diabetes Federation (IDF), American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI), MS is defined as the combination of at least three of the following conditions: increased plasma glucose (≥ 100 mg/dl), hypertension (≥ 130/85 mmHg or systemic arterial hypertension treatment), hypertriglyceridaemia (≥ 150 mg/dl), low high-density level cholesterol (HDL, < 40 mg/dl) and/or elevated abdominal circumference (≥ 94 cm + ethnicity-specific values)19.
MS is a major public health challenge worldwide since it is associated with a five-fold elevated risk of T2DM and a two- to three-fold risk of cardiovascular disease20. MS predicts diabetes independently of other factors. However, obesity worsens the diabetes risk associated with MS or impaired glucose tolerance, due to its relation to insulin resistance and due to being the central element of MS21. Data from the third National Health and Nutrition Examination Survey (NHANES III) in adults aged 50 years or older indicated that the prevalence of coronary heart disease was greatest in individuals with MS and DM combined22.
Circulating blood glucose binds to, and therefore glycates, the red blood cell protein haemoglobin. This glycation occurs proportionally to the blood glucose concentration. By measuring the percentage of glycated haemoglobin (HbA1c) in the blood, the average blood glucose over the past 2 to 3 months and a person’s success in controlling their blood glucose can be estimated23.
According to the position statement published by the ADA in 201824, it is suggested that the HbA1c should be less than 7% for non-pregnant adults, which is an average glucose concentration of 154 mg/dl or 8.6 mmol/l (Table 1-2). However, it can be less stringent; for example, in patients with a history of severe hypoglycaemia, long-standing diabetes and limited life expectancy, < 8% is acceptable. The HbA1c test should be conducted at least two times per year in patients who are meeting the treatment goals and who have stable glycaemic control, and quarterly in patients whose therapy has changed or who are not meeting glycaemic goals24.
Table 1-2 The relationship between haemoglobin A1c (A1C) and estimated average glucose (eAG, calculated by the formula eAG = 28.7 × A1c − 46.7)
| A1C | eAG | |
|---|---|---|
| % | mg/dl | mmol/l |
| 6.0 | 126 | 7.0 |
| 6.5 | 140 | 7.8 |
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