Global burden of Diabetes:Prevalence and projectionsBelllagio, March 16th 2004Peter H. Bennett, M.B., F.R.C.P.National Institute of Diabetes and Digestive and Kidney Diseases,Phoenix, Arizona, U.S.A.

OutlinePrevalence of DiabetesEstimates of future prevalence (projections)Mortality attributable to diabetesEffect of the epidemic on rates of complicationsProjections for ESRD

Global Projections for the Diabetes Epidemic: 2000-2030 (in millions)NA19.733.972%LAC13.333.0248%EU17.825.141%A+NZ1.22.065%SSA 7.118.6261%World2000 = 171 million2030 = 366 millionIncrease 213%China20.842.3204%Wild, S et al.: Global prevalence of diabetes:Estimates for 2000 and projections for 2030 Diabetes Care 2004 In pressIndia31.779.4251%MEC20.152.8263%

Estimated Number of People with Diabetes in 2000 and 2030 (and % change)Wild, S et al.: Global prevalence of diabetes: Estimates for 2000 and projections for 2030 Diabetes Care 2004. In press+176%+26%-13%

Estimated Number of People with Diabetes in 2000 and 2030 (and % change)Wild, S et al.: Global prevalence of diabetes: Estimates for 2000 and projections for 2030 Diabetes Care 2004 In press+308%+247%+189%

Estimated Number of People with Diabetes in 2000 and 2030Wild, S et al.: Global prevalence of diabetes: Estimates for 2000 and projections for 2030 Diabetes Care 2004 In press+242%+212%+75%

Are these projections realistic?

Based on:1990s estimates of diabetes prevalenceDemographic projectionsAssume constant (current) age-sex specific prevalence of diabetes

Changing Prevalence of Type 2 Diabetes

No of persons with Physician-diagnosed Diabetes in USA by yearData from the US National Health Interview Survey: http://www.cdc.gov/diabetes/statistics/prev/national/fig1.htm

Diabetes in the United States1958-1993Prevalence (%)> 65 years55-65 years45-54 years< 45 yearsData from the US National Health Interview Survey

Diabetes in the United States1980-2000Prevalence (%)< 45 years65-74years

45-64years75+yearsData from the US National Health Interview Survey:http://www.cdc.gov/diabetes/statistics/prev/national/fig3.htm

Why were former projections inaccurate?They were based on demographic changes (which are very predictable)

The epidemic of diabetes is driven by other factors (some or perhaps most of which may be reflected in occurrence of IGT and IFG)

Importance of IGT and IFG

Impaired Glucose Homeostasis'Impaired Fasting Glucose' (IFG) FPG of 100-125mg/dl [5.6 -

Incidence of Diabetes in people with Impaired Glucose Homeostasis

Prevalence and Incidence of Diabetes (%) in Impaired Glucose Homeostasis

Projections of Numbers with Diabetes* among persons aged 40-74years in USA (Millions)*Based on diabetes incidence (5% / year) in the 20% of persons with impaired glucose homeostasis; 300,000 diabetes deaths / year; Net increase = c.700,000 cases of diabetes / year

Proportion of new cases of Diabetes (%) in persons with NGT and Impaired Glucose Homeostasis

Projections of Numbers with Diabetes* among persons aged 40-74years in USA (Millions)*Based on diabetes incidence (5% / year) in the 20% of persons with impaired glucose homeostasis; 40% of new cases from persons with NGT; 450,000 diabetes deaths / year Net increase = c.830,000 cases of diabetes / year

Mortality attributable to diabetes

Number of Deaths with Diabetes as Underlying Cause of Death, United States, 1980-1996.

CDC, Diabetes surveillance, 1999

Excess Deaths attributable to DiabetesExcess mortality =No of deaths in DMs Expected no. if not DM

No of DM deaths = (RR of death in DM x No. with DM)Expected No. = Mortality rate in non DMs*No. with DM

Mortality rate; RR of death in DM; No. with diabetes

Global Projections of Excess Deaths attributable to Diabetes (in 000s) and percent of all deaths in year 2000AMRA251.19.75%AMRD32.26.1%EUR609.06.4%WPR469.34.1%AFR319.22.6%WorldIn 2000 = 3.164 million(5.4% of all deaths)

SEAR1154.16.9%Roglic et al.: Burden of mortality attributable to diabetes:Estimates for the year 2000. In preparationEMR125.37.2%AMRB194.07.6%

Consequences of the Epidemic

Consequences of Epidemic Disproportionate increase in duration-related complications Increase in number with diabetes

Effect of Epidemic of Diabetes on Duration-related complications16 new cases/yr. Death occurs after 30y DM; Complication incidence 50% after 15y DMAfter 30 years No. of new cases equals no. of deaths.05101520253035404550Time (years)0150300450No. of Cases01020304050Percent withcomplicationsCumulative No. of DM cases% with DM>15y durationPrevalence of complications (%) among those with DM

Incidence of Type 2 Diabetes in Pima Indians in two time periods1965-751975-85Time Period01020304050Incidence per 1000 person-yearsAge-sex adjusted rates60% increase

Age-standardized mortality from Ischemic Heart Disease in diabetic and non-diabeticPima Indians aged 35+ years, (30 year follow-up)1965-741975-84 Non-diabetic1985-941965-741975-84 Diabetic1985-940123456Mortality /1000 person-years

Renal disease

1965197019751980198519901994Year0510152025CasesDialysisDeathsFrequency of Renal Failure among Pima Indians

1965-741975-841985-94Time Period04812Cases per 1000/yearIncidence of Renal Failure

Number of persons beginning treatment for ESRD attributable to diabetes in USA by year http://www.cdc.gov/diabetes/statistics/esrd/Fig1Detl.htm

DIABETES IN END-STAGE RENAL FAILURE: AUSTRALIA 1980 - 2000 Year of EntryNumber of DiabeticsNumber of New Patients

Crude and Age-adjusted incidence of ESRD related to diabetes in the United States1984-2001Incidence/100,000 Diabetic personsAge-adjusted rateData from the US Renal Data System:http://www.cdc.gov/diabetes/statistics/esrd/fig7.htmCrude rate

Projections for number of patients with diabetes initiating ESRD treatment in USA** Assuming current incidence rates for initiating ESRD treatment remain constant

SummaryBased on demographic changes alone:The numbers of persons with diabetes in the world will more than double in the next 30 yearsIn developed countries they will increase by 30-70% (mostly in older persons) In developing countries they will increase by c. 250% (mostly in 45-64y age group)These projections do not take into account any increase that is attributable to future increases in obesity

Summaryc.3.2 million (excess) deaths were attributable to diabetes in year 2000. In the USA this is 9% of all deathse.g. In USA c.200,000 excess deaths vs. 14,500 for AIDsThe numbers of deaths attributable to diabetes in future years will increase especially in developing countries

SummaryBecause of the current epidemic of diabetes, reflected in increasing age specific prevalence, the proportion of the diabetic population with complications will increase.This will result in a greater relative increase in complications than in diabetes prevalence.Because serious complications e.g. ESRD, typically develop after 15-20 years duration, the incidence of ESRD due to diabetes will continue to increase for at least the next 20 years

Thank you

Age-adjusted incidence of ESRD related to diabetes in the United States1984-2001Incidence/100,000 Diabetic personsWhite femaleBlack femaleHispanic maleBlack maleData from the US Renal Data System:http://www.cdc.gov/diabetes/statistics/esrd/fig5.htmWhite maleHispanic femaleAmer. Indian maleAmer. Indian female

Are there better ways to predict future trends?Incidence = No. of new cases/ period of timeMortality = No. of deaths/ period of timePrevalence=Cumul.incidence Cumul. Mortality = Number of cases at a point in timeFuture no. of cases = No. of prevalent cases + no. of new cases- No. of deaths(among all cases)