A GBD study attributes 48,307 breast-cancer deaths in 2023 to high blood sugar

High fasting plasma glucose is an established risk factor for breast cancer, but up-to-date estimates of how much of the global breast-cancer burden it accounts for have been scarce [s1]. An analysis published in PLOS One on 21 October works through that question using the Global Burden of Disease database, the same machinery that each year attributes a share of the world's death and disability to 88 separate risk factors [s1][s2].

What the study measured

The researchers performed a descriptive analysis of the burden of female breast cancer attributable to high fasting plasma glucose, drawing on the GBD 2023 database [s1]. The core metrics were the absolute number of deaths and disability-adjusted life years — DALYs, a measure that combines years of life lost to early death with years lived with disability. To compare populations with different age structures fairly, they also used the age-standardised mortality rate and the age-standardised DALY rate, and they summarised change over time with the average annual percentage change [s1]. For the future, they fitted a Bayesian age-period-cohort model to project the burden from 2024 to 2050 [s1].

The numbers

In 2023, high fasting plasma glucose was linked to 48,307 female breast-cancer deaths and 1,406,186 DALYs worldwide [s1]. Over the study period the direction of travel was upward: from 1990 to 2023, both the age-standardised mortality rate and the age-standardised DALY rate rose, with an average annual percentage change of 0.28% for mortality (95% confidence interval 0.18% to 0.38%) and 0.44% for DALYs (95% CI 0.37% to 0.51%) [s1]. In absolute terms, the age-standardised mortality rate climbed from 0.92 to 1.00 per 100,000 and the DALY rate from 26.22 to 30.17 per 100,000 between those years [s1].

The burden was not spread evenly across the 21 GBD regions or the 204 countries and territories in the database [s1]. The study found only a weak correlation between a country's Socio-demographic Index — a composite of income, education and fertility — and its age-standardised mortality rate (Spearman's rho 0.20, P = 0.004), and no significant correlation with the DALY rate [s1]. The heaviest burden fell in the low-middle SDI quintile [s1]. The projection model pointed the same way as the history: it estimated that both rates would keep rising from 2024 through 2050 [s1].

What this does and does not establish

This is the part that matters for how the findings should be read, and the authors are unusually direct about it. The analysis is ecological and population-level [s1]. It takes the GBD system's estimate of how much breast-cancer burden is statistically attributable to high fasting plasma glucose and tracks that estimate over time and across places; it does not follow individual women, and it cannot show that lowering blood glucose would prevent breast-cancer deaths [s1]. Whether glucose-lowering interventions can actually reduce breast-cancer incidence, the authors write, remains to be established in prospective interventional studies [s1].

That caveat is not a formality. Attributable-burden figures of this kind inherit every assumption in the underlying risk model — the size of the association between glucose and breast cancer, how exposure is distributed, and how the GBD machinery apportions cause [s2]. When those inputs shift, the attributable numbers shift with them, which is why the right way to read a 0.28%-a-year rise is as a modelled trend in an estimate, not a directly counted death toll.

Why it still matters

What the study adds is a sizing and a direction. It places a specific, rising share of the world's female breast-cancer burden on a metabolic risk factor that is itself becoming more common, and it shows that share concentrating in lower-middle-income settings rather than the richest ones [s1]. The authors' conclusion follows from that pattern rather than from any single trial: glycaemic management and metabolic risk-factor control deserve consideration within breast-cancer prevention frameworks, and the regions carrying the heaviest attributable burden are the logical place to aim future research [s1]. The claim is about where to look next, not about a treatment that is ready to deploy.

The signal is worth taking seriously even so. High fasting plasma glucose is one of the metabolic risk factors the Global Burden of Disease project tracks across the whole of human health, and its reach is widening as populations age and the prevalence of raised blood sugar climbs [s2]. A risk factor that is becoming more common, and whose attributable share of a major cancer is estimated to be rising rather than falling, is exactly the kind of trend that is cheaper to act on early than late — provided the interventional evidence the authors call for is actually gathered [s1]. For now the finding is a map, not a prescription: it marks where the attributable burden sits and which way it is moving, and leaves the question of what to do about it to the trials that have not yet been run [s1].