Diabetes mellitus can affect the muscle in several ways.
Patients with diabetes mellitus can develop contracture of digits and limbs as a result of soft tissue thickening in these areas. This can lead to wasting of the muscle from disuse. This is referred to as atrophy.
Diabetes mellitus promotes atherosclerosis which impairs the circulation to many tissues of the body. When the muscles of the limbs are affected, the decreased blood flow can lead to cramping and to painful walking (peripheral vascular disease resulting in claudication). In the worse case scenario – this can lead to death (infarction) of the localized areas of muscle. This is characterized by local pain in the involved area. Blood testing can demonstrate elevated muscle enzymes (CPK, aldolase). When the heart muscle is affected by such atherosclerosis, it can lead to heart attack.
Diabetes mellitus can also damage the nerves that supply the hands and feet. This can lead to inadequate nerve supply and further muscle wasting. Persons with longstanding diabetes mellitus can develop pain, and muscle twitching, in addition to muscle wasting of the muscles around the shoulders and hips (limb girdle wasting). This condition is referred to as diabetic amyotrophy.
In the majority of people with diabetes, muscle strength is preserved well enough to allow for modest physical activity under a doctor’s supervision, This is not an excuse for someone with diabetes to refrain from physical activity!