Relationships between plasma and erythrocyte fatty acids in the de novo lipogenesis pathway, and metabolic disorders in French elderly patients

Undernutrition has been identified as a major contributing factor to morbidity and mortality in hospitalized aged patients. The lipid calorie undernutrition may lead to de novo lipogenesis (DNL); among the endogenous fatty acids, 16: 1(n-9) and 18:1 (n-7) have been previously associated with a higher risk of sudden cardiac arrest (SCA). The aim was to examine possible associations between the fatty acids in the DNL pathway present in both plasma and erythrocytes of 188 patients aged 847 years (48 men and 140 women) entering the geriatric department for evaluation and rehabilitation, and their metabolic disorders. The 18:1(n-7) content in plasma cholesteryl esters (CE) was significantly higher in men (1.67 vs. 1.58% in women; P < 0.05). An inverse relationship was found between 18:1 (n-7) and the two precursors of essential fatty acids (EFA), that is linoleic acid [18:2 (n-6); LA] and alpha-linolenic acid [18:3 (n-3); ALA]. Moreover, an inverse relationship was found between 16: 1(n-9) and LA. Sixty-four percent of men suffered from dysglycemia versus 46% of women (P < 0.05). These patients were characterized by significantly higher content (+37%) of 16:1(n-7) which derives mostly from DNL. Prevalence of metabolic syndrome (MetS) was 30-40%, associated with a higher level of 18:0, regardless of sex. Practical applications: Improving nutrition for the elderly patients is a key challenge for rehabilitation. The diet of our oldest old patients was low in total calories and low in fat; it might be partly responsible for the levels of fatty acids from DNL observed. Further study is needed to investigate whether it is possible to reduce both 18:1 (n-7) and 16: 1(n-9) levels. We propose to test the improvement of diet for our oldest old patients by increasing fat up to 70g/d which is the lower limit of the recommended amounts.