The association of short-term memory and cognitive impairment with ghrelin, leptin, and cortisol levels in non-diabetic and diabetic elderly individuals.

Abstract

This study assessed short-term memory and biochemical indicators with the levels of ghrelin, leptin, and cortisol between cognitive impairment and normal older adults with or without diabetes. We enrolled 286 older adults (aged 65-85years) with or without diabetes from the local community. Short-term memory was assessed using pictures of common objects; cognitive functioning was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The physiological indexes assessed were plasma levels of fasting ghrelin and leptin, ghrelin level at 2_h after breakfast, 24-h urinary cortisol value, body mass index, and plasma cortisol levels at 8:00a.m., 4:00 p.m., and 12:00p.m. In both non-diabetic and diabetic subjects, short-term memory was significantly lower in the impaired cognition group (5.99±2.90 in non-diabetic subjects and 4.71±2.14 in diabetic subjects) than in the normal cognition group (8.14±2.23 in non-diabetic subjects and 7.82±3.37 in diabetic subjects). Baseline ghrelin level was significantly lower in the impaired cognition group (9.07±1.13ng/mL in non-diabetic subjects and 7.76±1.34ng/mL in diabetic subjects) than in the normal cognition group (10.94±1.53ng/mL in non-diabetic subjects and 9.93±1.76ng/mL in diabetic subjects); plasma cortisol levels at 8:00 a.m., 4:00 p.m., and 12:00p.m. were significantly higher in the impaired cognition group than in the normal cognition group, while no significant difference was observed in plasma levels of fasting leptin between different groups. Fasting plasma ghrelin and cortisol levels may be markers of cognitive decline and memory loss. It is possible that adjusting their levels may have a therapeutic effect, and this should be investigated in future studies.