Distal lower limb strength is reduced in subjects with impaired glucose tolerance and is related to elevated intramuscular fat level and vitamin D deficiency.
To quantify muscle strength and size in subjects with impaired glucose tolerance (IGT) in relation to intramuscular non-contractile tissue, the severity of neuropathy and vitamin D level.



A total of 20 subjects with impaired glucose tolerance and 20 control subjects underwent assessment of strength and size of knee extensor, flexor and ankle plantar and dorsi-flexor muscles, as well as quantification of intramuscular non-contractile tissue and detailed assessment of neuropathy and serum 25-hydroxy vitamin D levels.



In subjects with impaired glucose tolerance, proximal knee extensor strength (P = 0.17) and volume (P = 0.77), and knee flexor volume (P = 0.97) did not differ from those in control subjects. Ankle plantar flexor strength was significantly lower (P = 0.04) in the subjects with impaired glucose tolerance, with no difference in ankle plantar flexor (P = 0.62) or dorsiflexor volume (P = 0.06) between groups. Intramuscular non-contractile tissue level was significantly higher in the ankle plantar flexors and dorsiflexors (P = 0.03) of subjects with impaired glucose tolerance compared with control subjects, and it correlated with the severity of neuropathy. Ankle plantar flexor muscle strength correlated significantly with corneal nerve fibre density (r = 0.53; P = 0.01), a sensitive measure of small fibre neuropathy, and was significantly lower in subjects with vitamin D deficiency (P = 0.02).



People with impaired glucose tolerance have a significant reduction in distal but not proximal leg muscle strength, which is not associated with muscle atrophy, but with increased distal intramuscular non-contractile tissue, small fibre neuropathy and vitamin D deficiency.
Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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MM
Almurdhi
School of Healthcare Science, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK.
N D
ND
Reeves
Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
F L
FL
Bowling
Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
A J M
AJ
Boulton
Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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M
Jeziorska
Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester and Central Manchester NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.|Weill-Cornell Medicine-Qatar, Doha, Qatar.
R A
RA
Malik
D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D050154:Adiposity; D000368:Aged; D000842:Ankle; D002112:Calcifediol / Q000097:blood; D042241:Early Diagnosis; D005260:Female; D018149:Glucose Intolerance / Q000150:complications* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007717:Knee; D007866:Leg; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018908:Muscle Weakness / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D011115:Polyneuropathies / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D012720:Severity of Illness Index; D000071075:Small Fiber Neuropathy / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D014808:Vitamin D Deficiency / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology
D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol