Evaluasi Stabilitas Kadar Kolesterol Total Serum pada Penyimpanan Suhu 4°C dan −18°C

Latar Belakang: Pemeriksaan kadar kolesterol total merupakan salah satu pemeriksaan yang dipengaruhi oleh tahap pra analitik, terutama penyimpanan sampel. Penundaan pemeriksaan di laboratorium dapat menyebabkan sampel serum harus disimpan terlebih dahulu sehingga berpotensi memengaruhi stabilitas kadar kolesterol total dan menghasilkan pemeriksaan yang kurang akurat. Tujuan: Penelitian ini bertujuan untuk mengevaluasi stabilitas kadar kolesterol total serum pada penyimpanan suhu 4°C dan −18°C. Metode: Jenis penelitian ini adalah eksperimental semu dengan desain komparatif pretest-posttest. Sampel yang digunakan berupa 1 sampel serum dengan 9 kali pengulangan. Pemeriksaan dilakukan pada suhu ruang (T₀), kemudian disimpan pada suhu 4°C dan −18°C (T₁) selama 7 hari. Hasil: Penyimpanan serum selama 7 hari pada suhu 4°C menyebabkan penurunan rata-rata kadar kolesterol total sebesar 10,25%, sedangkan penyimpanan pada suhu −18°C menunjukkan peningkatan sebesar 2,71% dibandingkan nilai awal pada suhu ruang. Rata-rata kadar kolesterol total serum berturut-turut adalah 239,344 mg/dL pada suhu ruang, 214,822 mg/dL pada suhu 4°C, dan 245,822 mg/dL pada suhu −18°C. Hasil uji Wilcoxon Signed Rank Test menunjukkan terdapat perbedaan yang signifikan antara penyimpanan pada suhu 4°C dan −18°C terhadap kadar kolesterol total serum (Asymp. Sig. (2-tailed)=0,028; p<0,05).

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Background: The total cholesterol level examination is one of the tests affected by the pre-analytical stage, especially sample storage. Delays in laboratory testing can cause serum samples to be stored first, potentially affecting the stability of total cholesterol levels and leading to less accurate test results. Objective: This study aims to evaluate the stability of total serum cholesterol levels at storage temperatures of 4°C and −18°C. Method: This study is a quasi-experimental, pretest-posttest design. The sample used consisted of 1 serum sample with 9 repetitions. The examination was conducted at room temperature (T₀), then stored at 4°C and −18°C (T₁) for 7 days. Results: Storing serum for 7 days at 4°C caused a decrease in the average total cholesterol level by 10.25%, while storage at −18°C showed an increase of 2.71% compared to the initial value at room temperature. The average total serum cholesterol levels were 239.344 mg/dL at room temperature, 214.822 mg/dL at 4°C, and 245.822 mg/dL at −18°C. The Wilcoxon Signed Rank Test results showed a significant difference between storage at 4°C and −18°C regarding total serum cholesterol levels (Asymp. Sig. (2-tailed) =0.028; p<0.05).