Collection of General Patient Information and Clinical Indicators
General information collected included patient age, gender, height, weight, and BMI. Clinical indicators encompassed fasting plasma glucose (FPG), glycated hemoglobin (HbA1C%), bone mineral density (BMD) and T-scores of the lumbar spine, femoral neck, and total hip, handgrip strength, time to complete five chair stands, appendicular skeletal muscle mass (ASM), Short Physical Performance Battery (SPPB) scores, body composition metrics, Activities of Daily Living (ADL) scores, and fall risk assessments.
Definition and Measurement of Osteoporosis
Osteoporosis was assessed using a dual-energy X-ray absorptiometry (DXA) scanner (Lunar iDXA) to measure the BMD and T-scores of the lumbar spine and hip. According to the Guidelines for the Diagnosis and Treatment of Primary Osteoporosis (2022)[8], osteoporosis is diagnosed in men aged 50 and older or postmenopausal women if they have a T-score ≤ -2.5 at any site (lumbar spine or hip) or a history of fragility fractures.
Definition and Measurement of Sarcopenia
According to the 2019 consensus by the AWGS, sarcopenia is defined based on muscle mass, muscle strength, and physical performance. Possible sarcopenia is indicated by decreased muscle strength and/or physical performance. Sarcopenia is diagnosed when there is reduced skeletal muscle mass along with either decreased muscle strength or physical performance. Severe sarcopenia is identified when all three conditions are present.
Muscle Mass: Measured using the InBody S10 body composition analyzer through bioelectrical impedance analysis (BIA). Muscle mass is assessed using the Appendicular Skeletal Muscle Mass Index (ASMI), calculated as limb skeletal muscle mass (kg) divided by height squared (m²), with thresholds of ≤ 7.0 for men and ≤ 5.7 for women.
Muscle Strength: Evaluated using a baseline hand dynamometer (CH43100) digital grip strength dynamometer. Grip strength is measured three times for each patient, with 15-second intervals between measurements, and the average value is recorded. Decreased muscle strength is defined as < 28 kg for men and < 18 kg for women.
Physical Performance: Assessed using the Short Physical Performance Battery (SPPB), introduced by Guralnik et al. in 1994. The SPPB includes three components: balance tests (side-by-side, semi-tandem, and tandem stands), gait speed test (4-meter walk), and chair stand test (time to complete five chair stands). Each component is scored from 0 to 4, with a total score ranging from 0 to 12. A total score of ≤ 9 indicates decreased physical performance.
Diagnosis of Osteosarcopenia
According to the Expert Consensus on Osteosarcopenia, osteosarcopenia is diagnosed when both the criteria for sarcopenia and osteoporosis are met simultaneously[9].
Statistical Analysis
Statistical analysis was performed using SPSS 25.0 software. Measurement data were described using mean ± standard deviation for normally distributed data, and group comparisons were conducted using the t-test. For non-normally distributed data, the median (upper quartile, lower quartile) was used for description, and group comparisons were performed using the Wilcoxon rank-sum test. Categorical data were described using frequencies and percentages, with group comparisons made using the χ² test or Fisher's exact test. The factors influencing osteosarcopenia in patients with type 2 diabetes were analyzed using binary logistic regression, presented with OR values, 95% CIs, and P-values, with a significance level set at P < 0.05.