Treating Prediabetes Prevents Functional Decline

Older adults with prediabetes or diabetes experienced faster physical functional decline and disability progression. 

Diabetes is associated with a higher risk of faster physical functional decline, but the impact of prediabetes has been unknown. Individuals with physical function decline are regarded to be in a pre-disability phase. A population-based cohort study compared the effects of diabetes and prediabetes on physical function and disability progression, and whether cardiovascular diseases (CVDs) have an association. Although there have only been a few previous studies on the association of prediabetes with poor physical function, the results have been inconsistent. A study in the U.K. observed that impaired glucose tolerance was associated with a 60% higher possibility of poor physical function. On the other hand, a Japanese study concluded there was no association between prediabetes, walking speed, and chair stand time. These discrepancies may be due to different measurements of physical function and prediabetes. 

There are not many studies that have analyzed the link between diabetes and incident physical impairment. 2,013 individuals aged 60 years and older participated in a longitudinal study and were monitored for up to 12 years. Diabetes was identified as hemoglobin (HbA1c) ≥6.5%; in participants free of diabetes, prediabetes was identified as HbA1c ≥5.7–6.4%, and normoglycemia was defined as HbA1c <5.7%. 650 participants had prediabetes, 151 diabetes, and 1,212 were considered to have normoglycemia.  

Data was collected by standard interviews, comprehensive clinical and physical examinations. Physical function was assessed with highly reliable tests, chair stand and walking speed tests. The chair stand test consisted of participants moving quickly from sitting to standing five times consecutively. Walking speed included walking 6 minutes at a self-selected pace or 2.4 minutes if performed in a limited space or reported slow walking. The worst scores were given to participants with a chair stand time of 75 seconds. Younger individuals (60 to 72 years) were reexamined every six years, and the older participants ( ≥78 years) every three years. The diagnosis of cardiovascular disease was collected through clinical examinations by physicians. For diabetes-related diagnoses, chronic conditions including depression, mood disorders, cerebrovascular disease, and peripheral neuropathy were collected. 

The participants with diabetes and prediabetes were older, with a higher BMI, hypertension, lower eGFR, more chronic diseases, and less physical activity than those with normoglycemia. Individuals with diabetes and prediabetes were observed to have a longer chair stand time and slower walking speed than those with normoglycemia. The results became stronger among individuals with uncontrolled diabetes. There was an annual increase in chair stand time 95% CI 0.14–1.34) and a 0.08 annual increase in the disability score (95% CI 0.01–0.14). 

The study found that not only diabetes but prediabetes was associated with faster physical functional decline and disability progression. This decline was significantly faster in the younger adults (60 to 72 years) but was not significant in older adults ( ≥78 years). These results were especially evident among those with uncontrolled diabetes, demonstrating the impact of glycemic control and older individuals’ lack thereof. The observations showed no significant interactions between prediabetes and sex on physical function or disability progression changes. The results of a faster deterioration were independent of the future development of diabetes. This study infers the possibility that CVDs may explain the excess odds of functional disability observed in individuals with diabetes. More studies would need to be conducted on the extent of this association. 

The observations highlight the detrimental impact of hyperglycemia on functional status and the importance of maintaining adequate glycemic control, especially in older adults. The analysis also showed that not all older adults would benefit from strict glycemic control due to the complications. To conclude, glycemic targets should be specifically tailored to individuals considering their physical and cognitive functional status, comorbidities, and remaining life expectancy. 

Practice Pearls: 

• Diabetes and prediabetes are associated with faster physical functional decline and disability progression in older adults. 
• Individuals with diabetes and prediabetes functional decline would benefit from maintaining glycemic control. 
• More studies need to be conducted on the association between CVDs and functional decline. 

Shang, Y et al. Not Only Diabetes but Also Prediabetes Leads to Functional Decline and Disability in Older Adults. Diabetes care 2021; June 2020 

Brenda Oppong, PharmD Candidate, LECOM School of Pharmacy