Muscle quality is also better with good control but muscle mass did not show any significant effect from higher HbA1c’s in the study.…
People diagnosed with diabetes tend to experience lower muscle strength in comparison to those without diabetes. As a result, these people have a higher risk of functional disability and limitation of mobility. Unfortunately, up to now there have been no studies to prove the relationship of hyperglycemia with longitudinal changes in muscle function.
Researchers used data from the Baltimore Longitudinal Study of Aging (BLSA) to examine the hypothesis that hyperglycemia is associated with decreased muscle strength, mass, and quality. These data are not associated with physical activity or the presence of peripheral neuropathy.
A total of 984 participants aged 25–96 years who had had HbA1c, knee extensor strength, muscle mass, muscle quality, and thigh cross sectional area measured at least one visit at baseline, were included. The researchers also reexamined the participants up to 7.5 years for collecting data purpose. The participants were categorized by HbA1c quartile: quartile 1 (<5.5% or <37 mmol/mol), quartile 2(5.5–5.79% or 37-40 mmol/mol), quartile 3(5.8–6.09% or 40-43 mmol/mol), and quartile 4 (≥6.1% or ≥43 mmol/mol).
The result showed that the higher HbA1c quartiles, the older, heavier and taller participants were. There were fewer white participants in higher HbA1c quartiles but there were no differences in sex and physical activity level. Muscle strength was significantly lower in higher HbA1c quartile (-4.7 ± 2.30 N.m) and lower P value trend (P=0.02). After adjustment for physical activity, muscle strength was still significantly lower in the higher HbA1c quartile (-4.67 ± 2.32 N.m) but the P value trends were unchanged (P=0.045). After full adjustment for peripheral neuropathy, muscle strength was lower in higher HbA1c quartile (-4.47±2.32 N.m) and borderline significant of P value trend (P =0.05).
Mixed-effects regression models were used to evaluate differences in muscle quality. Muscle quality was significantly lower in the higher HbA1c quartile (-0.32±0.15 N.m/kg; P value trend=0.02).
After adjusting weight and height, the association between muscle quality across HbA1c was attenuated. In contrast, muscle mass including leg lean mass, total body lean mass and thigh CSA did not significantly differ across HbA1c.
The researchers concluded that HbA1c could lower muscle strength and muscle quality in comparison to normoglycemia with aging but this effect still remains unclear and should be explored in future studies.
- Higher HbA1c, a marker of chronic hyperglycemia, lowers muscle strength and muscle quality in comparison to normoglycemia.
- Muscle mass was not significant different across HbA1c level.
- Patients should be informed that better glycemic control can help to preserve muscle function.
Kalyani R. Hyperglycemia predicts persistently lower muscle strength with aging. Diabetes Care. Jan 2015; 38: 82-90.