Ten Questions about Diabetes Mellitus

Question 6. Which of the following best refl ects the association between blood glucose level and mortality in people with type 2 diabetes? There is a positive, although weak, association between increased glucose and increased mortality There is a positive, and very strong, association between increased glucose and increased mortality There is no association between glucose level and mortality Question 7. For people with healed diabetic foot ulcers, what is the 5-year cumulative rate of ulcer recurrence? 15% 30% 45% 66%


Question 6. Which of the following best refl ects the association between blood glucose level and mortality in people with type 2 diabetes?
There is a positive, although weak, association between increased glucose and increased mortality There is a positive, and very strong, association between increased glucose and increased mortality There is no association between glucose level and mortality Question 7. For people with healed diabetic foot ulcers, what is the 5-year cumulative rate of ulcer recurrence? 15% 30% 45% 66% Question 8. Which of the following interventions for preventing foot complications in people with diabetes is best supported by evidence?
Therapeutic footwear for preventing ulcer recurrence Screening and referral to foot care clinics to prevent major amputations in those at high risk Education programs for preventing ulcer recurrence, serious foot lesions, and major amputations Question 9. What proportion of patients with type 1 diabetes have thyroid peroxidase autoantibodies?

About one in fi ve
About one in ten About one in 100 Question 10. Which of the following best refl ects the evidence from randomized controlled trials on the optimum HbA1C for people with diabetes?
These trials found that development or progression of complications increases progressively as HbA1c increases above the nondiabetic range, and that there is a glycemic threshold above which there is a risk of complications These trials found that development or progression of complications increases progressively as HbA1c increases above the nondiabetic range, but there is no lower glycemic threshold for the risk of complications

Ten Questions about Diabetes Mellitus
This quiz is related to the Research in Translation article in the December issue of PLoS Medicine (DOI: 10.1371/journal.pmed.0010058).

Answer 1. 170 million
Wild and colleagues estimated that the number of cases of diabetes worldwide in the year 2000 among adults 20 years of age and older was about 171 million [1]. Data on the prevalence of diabetes according to age and sex from a limited number of countries were extrapolated to all 191 World Health Organization member states and applied to United Nations' population estimates for the year 2000 and the year 2030. The authors estimated that there will be 366 million people with diabetes in the year 2030.

Answer 2. About $3,500 per patient
In one study performed in Israel, the approximate annual direct cost of intensive insulin treatment was around $3,300 per patient, which is about three times more than that of standard insulin treatment [1]. However, when other factors such as the reduction in complications are taken into account, such treatment appears to be cost-effective [2,3].

Answer 4. Around 30%
One study showed that the cumulative risk of proteinuria is similar in type 2 and type 1 diabetes-27% and 28%, respectively, after 20 years of diabetes [1]. Another showed that around 30% of patients with type 1 diabetes had developed sustained microalbuminuria within 20 years [2].

Answer 5. Tight blood pressure control
Although there have been no systematic reviews that prove the benefi t of any of these three interventions [1], there is, nevertheless, evidence to support a correlation between tight blood pressure control and a decreased rate of nephropathy progression [2,3,4,5]. Importantly, the United Kingdom Prospective Diabetes Study Group found that the control of blood pressure was a far more important intervention to prevent mortality than blood glucose control [5]. Answer 6. There is a positive, although weak, association between increased glucose and increased mortality A systematic review of 27 studies examining the relationship between blood glucose level and mortality in type 2 diabetes found a positive but weak association between high glucose and increased mortality [1].

Answer 7. 66%
Although the incidence of new ulcers is relatively lowaround 2% per year [1,2]-the risk of recurrence for people with healed diabetic foot ulcers is very high: the 5-year cumulative rate of ulcer recurrence is 66%, and the rate of amputation is 12% [3].
Answer 8. Screening and referral to foot care clinics to prevent major amputations in those at high risk One randomized, controlled trial, involving 2002 patients attending a general diabetes clinic, found that a diabetes screening program (involving referral to a foot clinic if high-risk features were present) reduced the risk of major amputation compared with usual care after two years [1]. One randomized, controlled trial involving 400 people with diabetes and previous foot ulcer but without severe deformity (mean age 62 years), found no signifi cant difference in rates of foot ulceration between patients using therapeutic footwear and those using usual footwear [2]. One systematic review identifi ed three randomized, controlled trials and one quasi-randomized trial evaluating the effects of education programs on the prevention of diabetic foot ulcers [3]. The trials were of poor methodological quality and had confl icting results.

Answer 9. About one in fi ve
The Belgian Diabetes Registry indicated that the prevalence of thyroid peroxidase autoantibodies is 22% in patients with type 1 diabetes [1].
Answer 10. These trials found that development or progression of complications increases progressively as HbA1c increases above the nondiabetic range, but there is no lower glycemic threshold for the risk of complications Two large randomized, controlled trials in people with type 1 and type 2 diabetes found that development or progression of complications increases progressively as HbA1c increases above the nondiabetic range [1,2]. The data suggested that that there is no lower glycemic threshold for the risk of complications-the better the glycemic control, the lower the risk of complications.