The prevalence of zinc deficiency and analysis of influencing factors in individuals aged 65 and over in the tokat province

Aim: Zinc deficiency is a significant public health concern worldwide, particularly in developing countries. As the second most abundant trace element in the human body after iron, zinc is a structural component of more than 300 enzymes. Therefore, zinc deficiency adversely affects numerous systems and organs, including the immune and nervous systems, growth and development, the urinary system, the gastrointestinal tract, and dermatological health. If left unaddressed, zinc deficiency can lead to serious health issues. This is especially critical in elderly individuals, who are at a higher risk of zinc deficiency. Various studies in the literature have demonstrated that zinc deficiency is more prevalent in the elderly population. This study aims to determine the prevalence of zinc deficiency in elderly individuals, investigate the underlying causes, identify its impact on various health outcomes, and develop strategies for preventing this deficiency. Method: This cross-sectional study was conducted to investigate the prevalence of zinc deficiency and its influencing factors among individuals aged 65 and over in Tokat province and its districts. The study population was reached through Family Health Units (FHU) in the center of Tokat and its districts, and the study was carried out between December 1, 2023, and May 31, 2024. The sample size was calculated using the Epi Info 7.0 program, yielding a target population of 496 individuals. Prior to the study, ethical approval and relevant permissions for conducting the research in primary care settings were obtained. The research was supported by Tokat Gaziosmanpaşa University Scientific Research Projects (BAP) Coordination Unit (project number 2023/80). All individuals who agreed to participate in the study were administered a face-to-face questionnaire consisting of five sections. The Mini Nutritional Assessment (MNA) test was applied to evaluate malnutrition in the elderly. In the test, a score below 17 indicated malnutrition, a score between 17 and 23.5 indicated a risk of malnutrition, and a score above 23.5 was considered normal. Subsequently, 1-2 cm hair samples were collected from the occipital region. The collected hair samples were washed, dried, dissolved, and analyzed using an inductively coupled plasma (ICP) device. Zinc deficiency was defined as a hair zinc level below 70 µg/g, based on reference values established by the International Zinc Nutrition Consultative Group (IZiNCG). The data obtained from the study were entered into a computer for analysis. Descriptive statistics, Mann-Whitney U, Kruskal-Wallis H, Pearson's chi-square test, Fisher's exact chi-square test, Spearman's correlation, and binary logistic regression analysis were performed using IBM SPSS version 20.0. A statistical significance level of p<0.05 was considered. Results: Among the 475 participants in our study, 54.1% (n=257) were male, and 45.9% (n=218) were female. The mean age of the participants was 70.91±6.47 years (range: 65-94 years). The median hair zinc level was found to be 125.36 (IQR: 164,80) µg/g. Factors such as gender, age groups, education and employment status, income-expense balance, place of residence, number of household members, appetite, number of main meals, nutritional knowledge, number of chronic diseases, pneumococcal vaccination, diabetes, hypercholesterolemia, renal failure, MNA score, and low consumption of red meat and legumes significantly affected zinc levels (p<0.005). Zinc deficiency was identified in 34,5% (n=164) of the participants. Zinc deficiency was influenced by factors such as employment status, income-expense balance, number of household members, smoking, coffee consumption, appetite, number of main meals, physical activity, hypertension, and cardiovascular disease (p<0.005). Additionally, participants with zinc deficiency had a higher frequency of infections, hair loss, and memory loss. Moreover, according to the MNA test, 4.0% of participants were malnourished, and 34,1% were at risk of malnutrition. Notably, nearly half (47,4%) of the malnourished individuals were found to have zinc deficiency. Conclusion: Our study reveals that zinc deficiency is prevalent among the elderly (34.5%) and is influenced by various factors and associated with multiple health issues. The higher prevalence of zinc deficiency among malnourished individuals highlights the close relationship between zinc status and nutritional health in the elderly population. These findings underscore the need for increased focus on preventing and managing zinc deficiency in elderly individuals. Furthermore, implementing preventive health measures to address zinc deficiency before it occurs will be crucial in managing various pathological conditions. Key words: Zinc, Zinc Deficiency, Prevalence, Malnutrition, Elderly