Dietary zinc intake and absolute lymphocyte counts in advanced stage of nasopharyngeal cancer patients

Background: Nasopharyngeal Cancer (NPC) patients experience a deficiency immune system due to a systemic inflammatory response. Anorexia due to inflammation and dysphagia, as well as the effects of therapy such as chemotherapy and radiotherapy in NPC, causes a decreased intake of macronutrients and micronutrients, including zinc. Long-term zinc deficiency affects both non-specific and specific immune components (lymphocytes, monocytes, macrophages, neutrophils). However, research regarding zinc intake and lymphocyte counts is still rarely carried out, especially in NPC patients in Indonesia. The population of Indonesia has a different dietary intake pattern from the population of western countries. Therefore, researchers intend to examine zinc intake and lymphocyte counts in NPC patients at Dr. Kariadi Hospital in Semarang, Indonesia. Aims: To determine the relationship between dietary zinc intake and Absolute Lymphocyte Counts (ALC) in NPC patients. Methods: This study was a cross-sectional study involving NPC patients undergoing first to third cycles of chemotherapy and aged 18-59 years at Dr Kariadi Semarang in July 2020-October 2022. Patients with hypoalbuminemia, experienced metastases, had other comorbid diseases, and had undergone radiotherapy were excluded from this study. Dietary zinc intake was measured using the Food Frequency Questionnaire (FFQ) for the last 14 days and ALC was measured using a heme analyzer at Dr Kariadi Hospital Laboratory. Statistical analysis used the Pearson and Spearman correlation test to measure the strength of the correlation between dietary zinc intake and ALC, and a one sample T test to determine whether participants' zinc intake differed from the Recommended Dietary Allowance (RDA). Results: The sample of this research was 35 subjects [20 male subjects (57.1%) and 15 female subjects (42.1%)]. The average dietary zinc intake of NPC patients undergoing chemotherapy at Dr Kariadi Hospital was 5.18 +/- 2.19 mg/day (5.83 +/- 1.63 mg/day and 4.32 +/- 2.58 mg/day for males and females, respectively). The results showed a positive correlation between dietary zinc intake and ALC in NPC patients (r = 0.41, p = 0.013; p < 0.05). ALC in NPC patients was influenced by zinc intake and protein intake (p < 0.05), but not energy intake, BMI, and age (p > 0.05). The zinc intake of men and women was significantly different compared to the RDA recommendation (p < 0.05). Conclusion: There is a significant and positive correlation between dietary zinc intake and absolute lymphocyte counts in NPC patients undergoing chemotherapy.