The proportions of people with diabetes who are undiagnosed, diagnosed but untreated, receiving treatment with suboptimal glycemic concentrations, and receiving treatment with optimal glycemic concentrations were estimated. The researchers found that an estimated 55.8 percent of people with diabetes aged 15 years and older were diagnosed with diabetes globally in 2023. Overall, 91.4 percent of people with diagnosed diabetes were on treatment; the proportion of people on diabetes treatment with optimal glycemic concentrations was 41.6 percent. Among all people with diabetes, 21.2 percent had optimal glycemic concentrations on treatment. Globally, the proportion of people diagnosed with diabetes increased by 8.3 percent between 2000 and 2023; the proportion receiving treatment and with optimal glycemic concentrations on treatment increased by 7.2 and 1.3 percent, respectively.