1.
Insulin resistance drives hepatic de novo lipogenesis in nonalcoholic fatty liver disease.
Smith, GI, Shankaran, M, Yoshino, M, Schweitzer, GG, Chondronikola, M, Beals, JW, Okunade, AL, Patterson, BW, Nyangau, E, Field, T, et al
The Journal of clinical investigation. 2020;130(3):1453-1460
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Non-alcoholic fatty liver disease (NAFLD) is a common complication of obesity and is associated with multiorgan insulin resistance, dyslipidaemia and an increased risk of diabetes and coronary heart disease. The aims of this study were to (a) determine hepatic de novo lipogenesis (DNL) [the liver’s biochemical process of synthesising fatty acids] in 3 distinct cohorts, (b) determine the relationships among hepatic DNL and intrahepatic [within the liver] triglyceride (IHTG) content, and (c) determine the effect of moderate (10%) weight loss. This study is a cross-sectional study which included a total of 67 men and women (mean age: 39 ± 1 years; 14 men and 53 women). Results highlight the importance of DNL in the pathogenesis of hepatic steatosis [build up of fats in the liver] and suggest that increases in daily 24-hour plasma glucose and insulin concentrations are major drivers of increased DNL in individuals with obesity and NAFLD. Additionally, moderate (10%) weight loss caused a marked decrease in both hepatic DNL and IHTG content. Authors conclude that increases in circulating glucose and insulin promote hepatic DNL in individuals with NAFLD. Whereas an improvement in insulin sensitivity and a decrease in hepatic DNL, are potentially important contributors to the decline in IHTG content associated with moderate weight loss.
Abstract
BACKGROUNDAn increase in intrahepatic triglyceride (IHTG) is the hallmark feature of nonalcoholic fatty liver disease (NAFLD) and is decreased by weight loss. Hepatic de novo lipogenesis (DNL) contributes to steatosis in individuals with NAFLD. The physiological factors that stimulate hepatic DNL and the effect of weight loss on hepatic DNL are not clear.METHODSHepatic DNL, 24-hour integrated plasma insulin and glucose concentrations, and both liver and whole-body insulin sensitivity were determined in individuals who were lean (n = 14), obese with normal IHTG content (n = 26), or obese with NAFLD (n = 27). Hepatic DNL was assessed using the deuterated water method corrected for the potential confounding contribution of adipose tissue DNL. Liver and whole-body insulin sensitivity was assessed using the hyperinsulinemic-euglycemic clamp procedure in conjunction with glucose tracer infusion. Six subjects in the obese-NAFLD group were also evaluated before and after a diet-induced weight loss of 10%.RESULTSThe contribution of hepatic DNL to IHTG-palmitate was 11%, 19%, and 38% in the lean, obese, and obese-NAFLD groups, respectively. Hepatic DNL was inversely correlated with hepatic and whole-body insulin sensitivity, but directly correlated with 24-hour plasma glucose and insulin concentrations. Weight loss decreased IHTG content, in conjunction with a decrease in hepatic DNL and 24-hour plasma glucose and insulin concentrations.CONCLUSIONSThese data suggest hepatic DNL is an important regulator of IHTG content and that increases in circulating glucose and insulin stimulate hepatic DNL in individuals with NAFLD. Weight loss decreased IHTG content, at least in part, by decreasing hepatic DNL.TRIAL REGISTRATIONClinicalTrials.gov NCT02706262.FUNDINGThis study was supported by NIH grants DK56341 (Nutrition Obesity Research Center), DK20579 (Diabetes Research Center), DK52574 (Digestive Disease Research Center), and RR024992 (Clinical and Translational Science Award), and by grants from the Academy of Nutrition and Dietetics Foundation, the College of Natural Resources of UCB, and the Pershing Square Foundation.
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Effectiveness and safety of citicoline in mild vascular cognitive impairment: the IDEALE study.
Cotroneo, AM, Castagna, A, Putignano, S, Lacava, R, Fantò, F, Monteleone, F, Rocca, F, Malara, A, Gareri, P
Clinical interventions in aging. 2013;8:131-7
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The number of people aged 65 years and over with mild vascular cognitive impairment is continuing to increase. Vascular disease can reduce cerebral perfusion, causing oxidative stress and neurodegeneration. Citicoline [pharmaceutical] inhibits apoptosis associated with cerebral ischemia and in several models of neurodegeneration has been able to potentiate neuroplasticity. The aim of this study was to assess the effectiveness and safety of oral citicoline in elderly people with mild vascular cognitive impairment. A total of 349 patients were included in the study who were assigned to open-label treatment with oral citicoline 500 mg twice a day in a fasting state or to no treatment (controls). Results show that citicoline is effective and safe in the treatment of mild vascular cognitive impairment. The treated group showed improvement in MMSE (Mini-Mental State Examination) scores, with an increase of 0.5 points shown over the course of the study. Authors conclude that further studies are required in order to confirm the findings of this study, and to further assess the efficacy and safety of long-term administration of a dietary supplement such as Cytidine-5′-diphosphate choline.
Abstract
BACKGROUND The studio di intervento nel decadimento vascolare lieve (IDEALE study) was an open multicenter Italian study, the aim of which was to assess the effectiveness and safety of oral citicoline in elderly people with mild vascular cognitive impairment. METHODS The study was performed in 349 patients. The active or citicoline group was composed of 265 patients and included 122 men and 143 women of mean age 79.9 ± 7.8 years selected from six Italian regions. Inclusion criteria were age ≥ 65 years, Mini-Mental State Examination (MMSE) score ≥ 21, subjective memory complaints but no evidence of deficits on MMSE, and evidence of vascular lesions on neuroradiology. Those with probable Alzheimer's disease were excluded. The control group consisted of 84 patients, including 36 men and 48 women of mean age 78.9 ± 7.01 (range 67-90) years. Patients included in the study underwent brain computed tomography or magnetic resonance imaging, and plasma dosage of vitamin B12, folate, and thyroid hormones. Functional dependence was investigated by scores on the Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) scales, mood was assessed by the Geriatric Depression Scale (GDS), and behavioral disorders using the Neuropsychiatric Inventory scale. Comorbidity was assessed using the Cumulative Illness Rating Scale. An assessment was made at baseline (T0), after 3 months (T1), and after 9 months (T2, ie, 6 months after T1). The main outcomes were an improvement in MMSE, ADL, and IADL scores in the study group compared with the control group. Side effects were also investigated. The study group was administered oral citicoline 500 mg twice a day throughout the study. RESULTS MMSE scores remained unchanged over time (22.4 ± 4 at T0; 22.7 ± 4 at T1; 22.9 ± 4 at T2), whereas a significant difference was found between the study and control groups, both in T1 and in T2. No differences were found in ADL and IADL scores between the two groups. A slight but not statistically significant difference was found in GDS score between the study and control groups (P = 0.06). No adverse events were recorded. CONCLUSION In this study, citicoline was effective and well tolerated in patients with mild vascular cognitive impairment. Citicoline activates biosynthesis of phospholipids in neuronal membranes, increases brain metabolism as well as norepinephrine and dopamine levels in the central nervous system, and has neuroprotective effects during hypoxia and ischemia. Therefore, citicoline may be recommended for patients with mild vascular cognitive impairment.