Race Differences In Associations Between Micronutrient Intake And Habitual Sleep Variability In Adolescents

Open Access
Daou, Carla
Graduate Program:
Public Health Sciences
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 13, 2018
Committee Members:
  • Duanping Liao, Thesis Advisor
  • Kristen H Kjerulff, Committee Member
  • Sleep variability
  • sleep duration
  • insomnia complaint
  • micronutrient
  • race
Objective: The objective plan of this study was to investigate the relations between micronutrients (Calcium, Magnesium, Zinc, Iron and Copper) and habitual sleep variability (HSV), mean sleep duration (HSD) and insomnia complaint (INS) and whether the associations between mean sleep duration and variability are modified by gender and race. Methods: We used data from 324 adolescents who participated in the Penn State Child Cohort follow-up examination. Actigraphy was used over seven consecutive nights to estimate nightly sleep duration. The seven-night mean and standard deviation of sleep duration were used to represent HSD and HSV, respectively. Insomnia complaint INS was also assessed in this study. The Youth/Adolescent Questionnaire (YAQ) was used to evaluate the participants’ daily nutrition and food intake behavior. Frequency of consumption of 152 food items were measured and then converted into a series of nutrient indices which was then converted to the amount of different nutrients consumed. 5 micronutrients were assessed: Calcium, Copper, Iron, Magnesium and Zinc. Linear regression models were used to study the association between habitual sleep patterns and micronutrient intake and whether these associations vary between gender and race, whereas logistic regression models were used to evaluate the associations between insomnia complaint and micronutrient intake. Results: After adjusting for age, race, sex, body mass index (BMI) and caloric intake, a decreased HSD was associated with an increase intake of Copper. For example, for every 1 unit increase in log (Cu), there is a 7.28 minutes decrease in HSD. The association between each of calcium, iron and magnesium and the sleep variability was race dependent. For example, among white people, sleep variability was decreased by almost 6 minutes, as compared to 3 minutes increase among non-white for 1 unit log increase in calcium intake, decreased by 4 minutes among white and increased by 4 minutes among non-white for every 1 log unit increase in iron, and decreased by 6 minutes in white as opposed to 5 minutes increase in non-white for every 1 log unit increase in Magnesium. Sex differences had no effect on the associations between habitual sleep patterns and micronutrient intake. No relationships between micronutrient intake and either of insomnia complaint and sleep variability were observed. Conclusion: Race modifies the associations between micronutrient intake and habitual sleep variability. There is an increase in HSV and not HSD in white people as compared to an increase in HSV in non-white when consuming calcium, iron and Magnesium. Increase in copper intake decreases sleep duration by about 7 minutes.