A team of international researchers have reported large variations in life expectancy for type 2 diabetics across 23 high-income countries with the lifetime risk of type 2 diabetes ranging from 16.3% for Scottish women to 59.6% for Singaporean men. They noted that despite declining lifetime risk and improvements in life expectancy for type 2 diabetics, the burden of type 2 diabetes “remains substantial”.
In the study, ‘Lifetime risk, life expectancy, and years of life lost to type 2 diabetes in 23 high-income jurisdictions: a multinational, population-based study’, published in The Lancet Diabetes and Endocrinology, the investigators sought to estimate lifetime risk, life expectancy and years of life lost for type 2 diabetes in the high-income setting.
The multinational, population-based study, obtained data from 24 databases from 23 countries (either whole countries or regions of a country - Australia; Austria; Canada; Denmark; Finland; France; Germany; Hong Kong; Hungary; Israel; Italy; Japan; Latvia; Lithuania; the Netherlands; Norway; Scotland; Singapore; South Korea; Spain; Taiwan; the UK; and the USA). The primary outcomes were lifetime risk of type 2 diabetes, life expectancy in people with and without type 2 diabetes, and years of life lost to T2DM.
The researchers modelled the incidence and mortality of T2DM in people with and without T2DM in sex-stratified, age-adjusted, and calendar year-adjusted Poisson models for each jurisdiction. Using incidence and mortality, they created life tables for people of both sexes aged 20–100 years for each jurisdiction and at two timepoints five years apart in the period 2005–19. Life expectancy from a given age was computed as the area under the survival curves and lifetime lost was calculated as the difference between the expected lifetime of people with versus without T2DM at a given age. Lifetime risk was calculated as the proportion of each cohort who developed type 2 diabetes between the ages of 20 years and 100 years.
From the 23 countries (1,577,234,194), there were 5,119,585 incident cases of T2DM, and 4,007,064 deaths in those with T2DM and 11,854,043 deaths in those without T2DM. The lifetime risk of type 2 diabetes ranged from 16.3% (95% CI 15·6–17·0) for Scottish women to 59.6% (58·5–60·8) for Singaporean men. Lifetime risk declined with time in 11 of the 15 jurisdictions for which two timepoints were studied.
For people with T2DM, the highest life expectancies were found for both sexes in Japan in 2017–18, where life expectancy at age 20 years was 59.2 years (95% CI 59·2–59·3) for men and 64.1 years (64.0–64.2) for women. Lithuania had the lowest life expectancy at age 20 years with T2DM observed in 2013–14 for (437 years [42.7–44.6]) for men and in 2010–11 in Latvia (54.2 years [53.4–54.9]) for women. Life expectancy in people with T2DM increased with time for both sexes in all countries, apart from for Spain and Scotland.
The authors also reported that:
The life expectancy gap between those with and without T2DM declined substantially in Latvia from 2010–11 to 2015–16 and in the USA from 2009–10 to 2014–15.
Years of life lost to T2DM ranged from 2.5 years (Latvia; 2015–16) to 12.9 years (Israel Clalit Health Services; 2015–16) for 20-year-old men and from 3.1 years (Finland; 2011–12) to 11.2 years (Israel Clalit Health Services; 2010–11 and 2015–16) for 20-year-old women.
The greatest decrease in years of life lost to T2DM was found in the USA between 2009–10 and 2014–15 for 20-year-old men (a decrease of 2.7 years).
“Despite declining lifetime risk and improvements in life expectancy for those with T2DM in many high-income jurisdictions, the burden of T2DM remains substantial. Public health strategies might benefit from tailored approaches to continue to improve health outcomes for people with diabetes."
The study was funded by the US Centers for Disease Control and Prevention and Diabetes Australia.
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