The diabetes pandemic: the latest figures from across the world Gojka Roglic

Number of persons with diabetes in the world 346 million in 2008 (WHO, 2011) 366 million in 2011 (IDF, 2011)

Predicted number of persons with diabetes in the world (IDF Atlas, 5th ed) 552 million in 2030

The Top 10s (number of people with diabetes) New in this edition: China takes the top spot, with India close behind. This is heavily influenced by the new study published in 2010. Our estimates are just under theirs at 90 million (compared to 91 million) and can be attributed to different age groups and a somewhat more conservative approach. Increases and changes in the position of countries relative to each other can be explained mostly by an ageing population and changes in urbanisation. Note, the BRIC countries are all in the top 10. Only the US is a high-income country. 4

The Top 10s (prevalence %) The Pacific Islands and MENA dominate this category. The rates are more than twice the global average. Changes again only take into account changes in the population structure and urbanisation. For Pacific Islands, urbanisation is 100% so it is just age changes that can be expected. New for this edition: IMPORTANT: Nauru is no longer number 1 This is due not only to new data from the region, but may also reflect the effects of mortality due to diabetes. The emergence of MENA – 6 out of the 10 countries are in MENA 5

Regional overview 6

Biggest changes will be in Africa, followed very closely by MENA Biggest changes will be in Africa, followed very closely by MENA. NAC and Europe will change the least. 7

Prevalence (%) by region From the curves we see that on average more men in younger age groups have diabetes than women, and that this relationship changes after 65. This may be due to a higher mortality in men than in women in older age groups. The overall numbers of men and women with diabetes is not dramatically different. Men: 185 million Women: 181 million 8

Prevalence (%) by age and sex From the curves we see that on average more men in younger age groups have diabetes than women, and that this relationship changes after 65. This may be due to a higher mortality in men than in women in older age groups. The overall numbers of men and women with diabetes is not dramatically different. 9

We can look at more detail by splitting middle income into upper and lower, and also separating low-income. We see that as countries develop from low-income to upper-middle income, the prevalence of diabetes increases. This is in line with what we would expect from urbanisation and changing lifestyles. If we look at more detail with the prevalence by income group and age we see that there is a consistently higher prevalence of diabetes for upper-middle income than high-income. We can also expect that as countries that are currently lower-middle income develop, the curve for prevalence of diabetes will shift higher and probably surpass that of high-income as well. 10

Proportion undiagnosed The International Diabetes Federation diabetes atlas methodology for estimating global and national prevalence of diabetes in adults. Guariguata L, Whiting D, Weil C, Unwin N. Diabetes Res Clin Pract. 2011 Nov 17. [PMID: 22100977] 11

Undiagnosed diabetes 12

Type 1 diabetes in the young 13

Healthcare expenditures USD 465 billion spent on healthcare for diabetes 11% of all healthcare spending is for diabetes USD 1,274 is spent on diabetes care per person with diabetes in 2011 The maps show us countries were there is high spending per person with diabetes, and high total spending on diabetes. The healthcare expenditures measure includes medical spending on diabetes by the health system as well as by people with diabetes. It does not include the indirect costs to society from lost productivity, absences from work, and the associated costs of care. In other words, this is a big underestimate of the true cost of diabetes. It is also important to note that some of this spending is necessary as part of care. However, some studies show that families pay 40-60% of medical care expenditures out of their own pockets for diabetes, which shows a disproportionate amount of the cost is borne by people with diabetes and their caregivers. 14

A population-based cost of illness study Prof. m. viswanathan Diabetes RESEARCH CENTRE AND M.V. HoSpital for Diabetes Chennai

Key findings The median annual direct cost was $525. The median annual indirect cost was $ 102. Extrapolating the direct and indirect cost to the total prevalence of India, the annual cost for diabetes would be $ 31.9 billion. A two way sensitivity analysis estimation showed a range of $25.5 billion - $38 billion with 10% variation either in the prevalence or in the cost of diabetes care.

How do patients pay for Diabetes care in India? 100% 11.7 6.2 Borrowing loan and mortgaging / selling property Savings plus other methods Insurance and company reimbursement Personal savings 10.4 15.2 80% 2 60 60% 40% 72 81.2 11.1 20% 28.8 0% <10000 INR 10001 – 30000 INR >30000 INR (206.95 – 620.86 US$) (>620.86 US$) Shabana Tharkar, Arut Selvi Devarajan, Satyavani Kumpatla, Vijay Viswanathan DRCP 89 2010 334-340

The global burden The number of people with type 2 diabetes is increasing in every country 80% of people with diabetes live in low-and middle-income countries 183 million people (50%) with diabetes are undiagnosed 18

The global burden The greatest number of people with diabetes are between 40 to 59 years of age 78,000 children develop type 1 diabetes every year 19

The global burden Diabetes caused 4.6 million deaths in 2011 Diabetes caused at least USD 465 billion dollars in healthcare expenditures in 2011; 11% of total healthcare expenditures in adults (20-79 years) 20

Regional highlights Africa: 78% of people with diabetes are undiagnosed Europe: the highest prevalence of type 1 diabetes in children Middle East and North Africa: 6 of the top 10 countries by diabetes prevalence North America and Caribbean: 1 adult in 10 has diabetes 21

Regional highlights South and Central America: 12.3% of all deaths were due to diabetes South-East Asia: almost one-fifth of the world’s people with diabetes live in just seven countries Western Pacific: 132 million adults have diabetes, the largest number of any region 22

The rising global prevalence of diabetes (millions)

Diabetes prevalence trend 1980-2008 (Danaei et al, 2011)

Is there a diabetes epidemic?

Possible causes of increasing diabetes Possible causes of increasing diabetes prevalence (from Colagiuri et al, Diabetologia 2005) Ageing of the population Younger age at onset Decreasing mortality Increasing incidence (risk)

Incidence of (diagnosed) diabetes UK population 25-79yrs 4.7/1000 p-y (Hippisley-Cox, 2009) Finnish population 40-69yrs 4.5/1000 p-y (Montonen, 2005) Chinese women 25+ yrs 5.4/1000 p-y (Villegas, 2008) US female nurses 38-63yrs 3.8/1000 p-y (Bazzano, 2008)

Possible causes of increasing type 2 diabetes Possible causes of increasing type 2 diabetes prevalence (Colagiuri et al, 2005) Ageing of the population Younger age at onset Decreasing mortality Explain only 20-25% increase in prevalence

Possible causes of increasing type 2 diabetes Possible causes of increasing type 2 diabetes prevalence (from Colagiuri et al, 2005) Ageing of the population Younger age at onset Decreasing mortality Increasing incidence! Explain only 20-25% increase in prevalence

1989 - 2005 RISING PREVALENCE OF DIABETES IN URBAN INDIA (Mohan, 2006) Within a span of 14 years, the prevalence of diabetes increased by 72.3%

Prevalence of overweight and obesity in population aged over 15 years (WHO STEPS Surveys)

BMI trends 1980-2008 ( Finucane et al, 2011)

Obesity/overweight trends 1980-2008 ( Finucane et al, 2011)

Obesity Increases Risk of Co-morbid States Women Men Type 2 diabetes Cholelithiasis Hypertension Coronary heart disease 6 6 5 5 4 4 Relative Risk 3 3 2 2 Two large-scale studies, the Nurses’ Health Study and the Health Professionals Follow-up Study, followed large groups of subjects for several years. Among these subjects, the risk of various diseases was closely related to BMI. Cholelithiasis, hypertension, and coronary heart disease all increased at comparable rates. A person with a BMI of 30 had approximately 3–4 times the risk of a person with a BMI of 21. Risk of type 2 diabetes, however, increased much more sharply. Reference: Willett WC et al. N Engl J Med. 1999;341:427-434. 1 1 <21 22 23 24 25 26 27 28 29 30 <21 22 23 24 25 26 27 28 29 30 BMI (kg/m2) BMI (kg/m2) Willett WC et al. N Engl J Med. 1999;341:427-434. 34

Relationship between BMI and diabetes prevalence in Asia (Boffetta, 2011)

Estimated projected urban and rural populations in the world, 1950-2030

Possible causes of increasing diabetes Possible causes of increasing diabetes prevalence (from Colagiuri et al, 2005) Ageing of the population Younger age at onset Decreasing mortality Increasing incidence (risk) Explain only 20-25% increase in prevalence

Diabetes and the risk of tuberculosis: a neglected threat to public health? (Stevenson et al, 2007)

The link of India’s diabetes epidemic to rising tuberculosis In India 18.4% of adults with pulmonary TB have diabetes, rising to 23.5% among those with infectious TB Diabetes accounts for 14.8% of adult pulmonary TB incidence, 20.2% of infectious TB incidence Diabetes makes a substantial contribution to the burden of incident tuberculosis in India, and the association is particularly strong for the infectious form of tuberculosis Stevenson et al. Diabetes and tuberculosis: the impact of the diabetes epidemic on tuberculosis incidence. BMC Public Health 2007, 7:234

IDF Atlas 2011: Diabetes and Tuberculosis Focus on the linkages between the two diseases and a review of the evidence Calculated the attributable cases of tuberculosis to diabetes Highlights areas where there is a high double burden Diabetes increases the chances of developing tuberculosis by 2.5 times at least. A person with diabetes and tuberculosis is more likely to fail tuberculosis treatment and more likely to die from tuberculosis than a person without diabetes. 40

These are countries with a high ‘double burden’ of diabetes and tuberculosis. They could be candidates for opportunistic screening of people with diabetes for TB and people with TB for diabetes. 41

Using the fact that we know that a person with diabetes has 2 Using the fact that we know that a person with diabetes has 2.5 times the chances of developing tuberculosis, we can calculate how much tuberculosis in a country may be due to diabetes. We see that for countries with a high burden of diabetes and a relatively low burden of tuberculosis, a large proportion of tuberculosis cases may be attributable to diabetes. Conversely, countries with a low diabetes burden will have fewer tuberculosis cases related to diabetes. 42

Prevalence of diabetes and Prediabetes among TB patients in Tamil Nadu, India Prof. m. viswanathan Diabetes RESEARCH CENTRE AND M.V. HoSpital for Diabetes

Objective To estimate the prevalence of diagnosed and undiagnosed diabetes among a cohort of tuberculosis patients registered under RNTCP in selected Tuberculosis Units in Tamil Nadu, India. To study the current diabetes care of TB patients with diabetes.

TB PROFILE OF THE STUDY SUBJECTS DIABETES(209) PRE DM(203) NON DM(415) P-VALUE Type of TB New Relapse Treat Default Treat Failure Others 172(82.3) 18(8.6) 16(7.7) 0(0) 3(1.4) 172(84.7) 13(6.4) 14(6.9) 1(0.5) 3(1.5) 352(84.8) 24(5.8) 18(4.3) 6(1.5) 15(3.6) 0.009 Pulmonary TB Extra-Pulmonary TB 186(89.0) 23(11.0) 31(15.3) 304(73.3) 111(26.7) <0.001 Smear Positive Smear Negative 126(67.7) 60(32.3) 112(65.1) 60(34.9) 188(61.8) 116(38.2) 0.39 Treatment Category Category-I Category-II 37(17.7) 63(15.2) 0.7

Deaths due to diabetes 4.6 million deaths due to diabetes in 2011 8.2% of all-cause mortality 48% in people under 60 More deaths due to diabetes than HIV/AIDS, malaria, and tuberculosis combined. GENDER There is no difference in the total number of deaths due to DM in men and women. But there are differences in the distributions. Diabetes accounts for a higher proportion in women than in men. This is due mostly to a higher rate of mortality from other causes in men than in women. TRENDS A 13.3% increase over the 4th edition, due mostly to higher prevalence of diabetes in several regions. There has been a documented decline in the deaths due to other NCDs in the world, but no similar decline for diabetes. ACCURACY The estimates use prevalence data combined with the relative risk of death from diabetes by age and region from existing mortality data. It certainly has gaps but is more accurate than that for diabetes from health statistics. This is because those statistics collect data from death reports and diabetes is rarely listed as the cause of death on a certificate, even though it may have been the underlying cause. 46

We see a different pattern for mortality We see a different pattern for mortality. If we look at total deaths, lower-middle income countries have the largest share of deaths of attributable to diabetes. This represents the intersect of development with poor health systems. However, we see that the mortality rate per 1,000 in the population (standardised) is more than double for all other income groups than for high-income which reflects the quality of health systems and their ability to affect diabetes-related death. 47

Deaths attributable to diabetes in India, 2011 (IDF Atlas 2011) 547,000 women 436,200 men

Diabetes deaths as % of all deaths in India, 2011 (IDF Diabetes Atlas, 2011)