Pathophysiological mechanisms and risk factors linking type 2 diabetes mellitus and sarcopenia: A narrative review

Table 1 Methods for diagnostic criteria by different working groups

Ref.	Muscle mass	Muscle strength	Physical performance
Cruz-Jentoft et al[7], EWGSOP2	DXA (ALM/height2): Male < 7.00 kg/m2, female < 6.00 kg/m2 or CT or BIA or MRI	Grip strength: Male < 27 kg, female < 16 kg	Gait speed: < 0.8 m/second or SPPB: ≤ 8 or TUG: ≥ 20 seconds
Bhasin et al[8], SDOC	Not specified	Grip strength: Male < 35.5 kg, female < 20 kg	Gait speed: < 0.8 m/second
Chen et al[9], AWGS	DXA (ASM): Male < 7.0 kg/m2, female < 5.4 kg/m2 or BIA (ASM): Male ≤ 7.0 kg/m2, female < 5.7 kg/m2	Grip strength: Male < 28 kg, female < 18 kg	Gait speed (6 m): < 1.0 m/second or 5 times stand-to-sit test: > 12 seconds or SPPB: ≤ 9
Fielding et al[10], IWGS	DXA (ALM/height2): Male < 7.23 kg/m2, female < 5.67 kg/m2	Not specified	Gait speed (4 m): < 1.0 m/second or standing up from a chair
Studenski et al[11], FNIH	DXA (ALM/BMI): Male < 0.789 kg/BMI, female < 0.512 kg/BMI	Grip strength: Male < 26 kg, female < 16 kg	Gait speed (4 m), gait speed (6 m): < 0.8 m/second

SDOC: Sarcopenia Definition and Outcomes Consortium; ALM: Appendicular lean mass; CT: Computed tomography; MRI: Magnetic resonance imaging; BMI: Body mass index; ASM: Appendicular skeletal mass; SPPB: Short physical performance battery; DXA: Dual-energy X-ray absorptiometry; BIA: Bioelectrical impedance.

Table 2 Studies on the effect of nutritional intervention on sarcopenia in type 2 diabetes mellitus

Nutrition intervention	Study design	Target population	Age (years old)	Research objectives	Results	Ref.
Vitamin intake	Prospective cohort study	T2DM patients	≥ 65	Loss of muscle mass	Vitamin D intake is associated	Takahashi et al[92]
Protein intake	Cross-sectional	T2DM patients	≥ 31	Muscle loss	Negative impact	Fanelli et al[151]
Protein supplementation	Randomized controlled study	T2DM patients	> 55	Physical performance and body composition	Positively improved	Argyropoulou et al[152]
BCAAs	Longitudinal study	T2DM patients	56.6 ± 10.6	Skeletal muscle loss	Negatively associated	Low et al[153]
Medical nutrition therapy	prospective study	T2DM patients	74 ± 6.0	Handgrip strength	Effective	Gaglio et al[154]
Omega-3 fatty acids intake	Cross-sectional	T2DM patients	74.2 ± 5.7	Sarcopenia	Negatively associated	Okamura et al[155]
BCAAs	Randomized controlled study	T2DM patients	65-80	Skeletal muscle mass	No significant correlation	Matsuda et al[156]
Exercise and protein intake	Cohort study	T2DM patients	≥ 65	Decreasing skeletal muscle mass index	Negatively associated	Hashimoto et al[157]
Resistance training and nutritional interventions	Prospective cohort study	Frail T2DM patients	79 ± 5.6	SPPB, maximal strength and power output	Positively improved	Izquierdo et al[158]

SPPB: Short physical performance battery; T2DM: Type 2 diabetes mellitus; BCAAs: Branched-chain amino acids.

Table 3 Studies on the effect of physical exercise on sarcopenia with T2DM

Physical exercise intervention	Study design	Duration	Target population	Research objectives	Results	Ref.
Low-volume walking high-intensity interval training	Randomized controlled trial	12 weeks	Older women with T2DM	Cardiovascular risk profile and physical capacity	Significantly improved	Marcotte-Chénard et al[159]
ST, aerobic training	Randomized, controlled trial	9 months	Normal-weight T2DM	HbA1c level and body composition	ST – significantly improved outcomes and increased lean body mass	Kobayashi et al[160]
Progressive sandbag exercise training	Randomized, controlled trial	12 weeks	Patients with T2DM and possible sarcopenia	HbA1c levels, muscle strength, and physical performance	Significantly improved	Chien et al[78]
Resistance exercise	Own-controlled before-and-after cohort study	24 hours	Older patients with T2DM and sarcopenia	Blood glucose	Lower blood glucose	Zhao et al[161]
In-Hospital exercise rehabilitation	Randomized, controlled trial	12 weeks	Middle-aged and elderly patients with T2DM and sarcopenia	Blood glucose, lipids, and muscle strength	Effectively improve	Shi et al[162]

T2DM: Type 2 diabetes mellitus; HbA1c: Glycosylated hemoglobin; ST: Strength training.