TG and hypothyroidism: A few participants (N = 5) had thyroid hormone levels indicative of hypothyroidism (defined as having either a total or free T4 level lower than the population-based range and having a TSH level higher than the population-based range), and 7 participants had thyroid hormone levels indicative of hyperthyroidism (defined as having either a total or free T4 level higher than the population-based range and having a TSH level lower than the population-based range).