<prompt> Which one of the following is true about GH?GH secretion increases after exercise, stress and hypoglycemiaGH secretion is maximum during eveningGH is produced equally in all age groupsGH decreases circulating IGF and Somatostatin  <response>: A GH secretion increases after exercise, stress and hypoglycemia GH secretion is pulsatile, with highest peak levels occurring at night, generally correlating with sleep onset. GH secretory rates decline markedly with age so that hormone levels in middle age are about 15 of pubertal levels. These changes are paralleled by an age-related decline in lean muscle mass. GH secretion is also reduced in obese individuals, though IGF-I levels may not be suppressed, suggesting a change in the set point for feedback control. Elevated GH levels occur within an hour of deep sleep onset as well as after exercise, physical stress, and trauma and during sepsis. Integrated 24-h GH secretion is higher in women and is also enhanced by estrogen replacement. GH secretion is profoundly influenced by nutritional factors 