Does vitamin D affect muscle strength and architecture? An isokinetic and ultrasonographic study

Sarcopenia in knee osteoarthritis: the association with clinical and sonographic findings, physical function, and nutrition

OBJECTIVE

The purposes of this study were to examine to (1) the relation between OA and sarcopenia and to identify the most practical, easily accessible, and inexpensive method for investigating sarcopenia; (2) evaluation of sarcopenia risk factors in patients with OA.

DESIGN

One hundred two patients with clinical and radiological diagnosis of knee osteoarthritis and 33 healthy control subjects were included in the study and all subjects were evaluated for sarcopenia. Dual-X-ray absorptiometry (DEXA) is used to measure body composition parameters and muscle thickness measurements with ultrasonography for diagnosis of sarcopenia.

RESULTS

The mean age of the group with sarcopenia was statistically higher than the other two groups (p < 0.001). The weight, body mass index (BMI), waist circumference, upper-mid-arm circumference, thigh, and leg circumference of osteoarthritis (OA) patients with sarcopenia were statistically lower than those of non-sarcopenic and control group (p < 0.01, p < 0.001). Body composition parameter results showed that sarcopenic patients had statistically lower values as fat mass, lean body mass, and skeletal muscle index (p < 0.001, p = 0.001, p < 0.001, respectively) than those of non-sarcopenic and control group and fat mass index values (p = 0.012) are lower than the non-sarcopenic group. With respect to sarcopenia, the effect of adiponectin and leptin levels were not detected. It was determined that body composition values measured with DEXA, ultrasonographic measures, isokinetic muscle strength assessment, handgrip strength, and gait speed had predictive values for sarcopenia.

CONCLUSIONS

We found that patients with sarcopenic OA were older, weaker, undernourished, and restricted in their level of physical activity in the study. Among the methods of determining sarcopenia, ultrasound becomes prominent with its practical, cheap, and easily accessible features. We think that our results will increase the awareness of the presence of sarcopenia in OA patients.

Relationship of vitamin D receptor gene polymorphism with sarcopenia and muscle traits based on propensity score matching

Background

Vitamin D receptor (VDR) gene polymorphism is reported to be associated with muscle mass and muscle strength. Loss of skeletal muscle mass and decreased muscle strength are the main characteristics of sarcopenia. In this study, the relationship of VDR gene polymorphism with muscle traits (muscle mass, muscle strength, and physical performance) and sarcopenia were studied in Xinjiang, China.

Methods

Totally, 205 sarcopenia patients were enrolled. Propensity score method was used to match control group. FokI and BsmI polymorphisms were genotyped using improved multiplex ligation detection reaction (iMLDR).

Results

Fok1, but not Bsm1, polymorphism was significantly associated with sarcopenia. Patients with Fok1 GG genotype were more likely to have sarcopenia. Both Bsm1 and Fok1 polymorphism were related to muscle traits. Patients with Bsm1 CT genotype had lower gait speed (GS) but higher skeletal mass index. Patients with Fok1 GG genotype had lower GS, and female subjects with the Fok1 GG genotype had lower handgrip strength (HS). GS was decreased in Bsm1 CT genotype than CC carriers. HS and GS were decreased in Fok1 GG genotype than AA carriers.

Conclusion

Fok1, but not Bsm1, polymorphism is associated with sarcopenia. Both Bsm1 and Fok1 polymorphism affect both HS and GS.