Dietary Zinc Intake and the Association of Insulin Level and HOMA-IR with Telomere Shortening in Mexican Children

Abstract

Purpose: The relationship between dietary zinc (Zn) intake, metabolic diseases, and telomere length has been little explored in the children population. This observational cross-sectional study assesses the association between obesity (OB), cardiometabolic traits, telomere length, and dietary Zn intake in children with normal weight (NW) and OB from Mexico City.

Methods: Anthropometric data, blood pressure, biochemical measurements, the homeostatic model assessment of insulin resistance (HOMA-IR) and leucocyte telomere length (determined by quantitative-PCR) were analyzed in 171 children with NW and 172 with OB. Furthermore, dietary Zn intake was evaluated in 117 children NW and 120 with OB.

Results: Telomere shortening was associated with fasting plasma insulin (FPI) and HOMA-IR in NW (beta coefficient [β]_FPI = -0.022 ± 0.008, p = 0.009; β_HOMA-IR = -0.096 ± 0.040, p = 0.020) and OB (β_FPI = -0.007 ± 0.002, p = 0.003; β_HOMA-IR = -0.034 ± 0.012, p = 0.005) children. Dietary Zn intake resulted negatively associated with FPI (β = -2.418 ± 0.764, p = 0.002) and HOMA-IR (β = -0.399 ± 0.014, p = 0.009) in children with OB. Then, in children with OB, the association between FPI, HOMA-IR, and telomere shortening was evaluated separately in groups of low, medium, and high dietary Zn intake (according to tertiles). The association between FPI, HOMA-IR, and telomere shortening was not significant in the high Zn intake group (P_FPI = 0.633; P_HOMA-IR = 0.567).

Conclusion: Our results suggest that a high Zn intake may ameliorate the telomere shortening related to high FPI and HOMA-IR.

Keywords: Dietary zinc intake; Insulin resistance; Mexican children; Obesity; Telomere length.