Tesis

Hubungan Kadar Vitamin D Serum dan Indeks Massa Otot pada Pasien Kanker yang Menjalani Radioterapi di RSUPN Cipto Mangunkusumo = The Relationship Between Serum Vitamin D Levels and Muscle Mass Index in Cancer Patients Undergoing Radiotherapy at Cipto Mangunkusumo National General Hospital.

Latar Belakang: Pasien kanker yang menjalani radioterapi berisiko mengalami gangguan fungsional, inflamasi, dan malnutrisi yang dapat menyebabkan penurunan massa otot rangka. Vitamin D merupakan mikronutrien yang berperan dalam metabolisme otot melalui regulasi sintesis protein dan aktivasi vitamin D receptor (VDR) pada serabut otot. Kadar vitamin D yang rendah dapat memperburuk proses katabolisme dan meningkatkan risiko penurunan massa otot. Namun, bukti mengenai hubungan kadar vitamin D serum dengan indeks massa otot pada pasien kanker yang sedang menjalani radioterapi di Indonesia masih terbatas. Metode: Penelitian ini merupakan studi potong lintang pada 82 pasien dewasa (18 tahun atau lebih) dengan berbagai jenis kanker yang sedang menjalani radioterapi di RSUPN Dr. Cipto Mangunkusumo. Dilakukan pemeriksaan kadar vitamin D serum (25(OH)D) dan indeks massa otot menggunakan alat BIA Seca. Analisis korelasi Spearman digunakan untuk menilai hubungan antara kadar vitamin D dan indeks massa otot, disertai analisis subgrup berdasarkan jenis kelamin dan status gizi. Hasil: Dari total 82 subjek, didapatkan nilai tengah kadar vitamin D sebesar 16,6 (6,2-43,5) ng/mL, dan 26,8% subjek memiliki indeks massa otot rendah. Terdapat korelasi positif yang signifikan antara kadar vitamin D serum dan indeks massa otot (r = 0,337; p = 0,02). Terdapat korelasi yang kuat pada laki-laki (r = 0,714; p < 0,001), sementara pada perempuan tidak dijumpai ada kemaknaan (r = 0,119; p = 0,512). Terdapat korelasi yang lebih kuat pada kelompok malnutrisi (r = 0,613; p = 0,026) dibandingkan kelompok tidak malnutrisi (r = 0,354; p = 0,003). Kesimpulan: Terdapat korelasi rendah yang signifikan antara kadar vitamin D serum dan indeks massa otot pada pasien kanker yang sedang menjalani radioterapi.
Kata Kunci: vitamin D, indeks massa otot, radioterapi, kanker


Background: Cancer patients undergoing radiotherapy are at increased risk of functional decline, inflammation, and malnutrition, all of which may contribute to loss of skeletal muscle mass. Vitamin D plays an important role in muscle metabolism through the regulation of protein synthesis and activation of vitamin D receptors (VDR) in muscle fibers. Low vitamin D levels may exacerbate catabolic processes and increase the risk of muscle wasting. However, evidence regarding the association between serum vitamin D levels and muscle mass index among cancer patients undergoing radiotherapy in Indonesia remains limited. Methods: This cross-sectional study involved 82 adult patients (aged ≥18 years) with various types of cancer undergoing radiotherapy at Dr. Cipto Mangunkusumo National General Hospital. Serum vitamin D levels (25(OH)D) and muscle mass index were measured using BIA Seca. Spearman correlation analysis was used to assess the association between vitamin D levels and muscle mass index, accompanied by subgroup analyses based on sex and nutritional status. Results: From a total of 82 subjects, the median serum vitamin D level was 16.6 (6.2–43.5) ng/mL, and 26.8% of subjects had low muscle mass index. There was a significant positive correlation between serum vitamin D levels and muscle mass index (r = 0.337; p = 0.02). A strong correlation was observed in males (r = 0.714; p < 0.001), while no significant association was found in females (r = 0.119; p = 0.512). In the malnourished group, the correlation was strong (r = 0.613; p = 0.026), compared with the non-malnourished group (r = 0.354; p = 0.003). Conclusion: A significant but low positive correlation was found between serum vitamin D levels and muscle mass index in cancer patients undergoing radiotherapy.
Keywords: vitamin D, muscle mass index, radiotherapy, cancer