Kidney and vascular function in adult patients with hereditary fructose intolerance

Objective: Previous studies have shown that patients with hereditary fructose intolerance (HFI) are characterized by a greater intrahepatic triglyceride content, despite a fructose-restricted diet. The present study aimed to examine the long-term consequences of HFI on other aldolase-B-expressing organs, i.e. the kidney and vascular endothelium. Methods: Fifteen adult HFI patients were compared to healthy control individuals matched for age, sex and body mass index. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cf-PWV) and endothelial function by peripheral arterial tonometry, skin laser doppler flowmetry and the endothelial function biomarkers soluble E-selectin [sE-selectin] and von Willebrand factor. Serum creatinine and cystatin C were measured to estimate the glomerular filtration rate (eGFR). Urinary glucose and amino acid excretion and the ratio of tubular maximum reabsorption of phosphate to GFR (TmP/GFR) were determined as measures of proximal tubular function. Results: Median systolic blood pressure was significantly higher in HFI patients (127 versus 122 mmHg, p = .045). Pulse pressure and cf-PWV did not differ between the groups (p = .37 and p = .49, respectively). Of all endothelial function markers, only sE-selectin was significantly higher in HFI patients (p = .004). eGFR was significantly higher in HFI patients than healthy controls (119 versus 104 ml/min/1.73m2, p = .001, respectively). All measurements of proximal tubular function did not differ significantly between the groups. Conclusions: Adult HFI patients treated with a fructose-restricted diet are characterized by a higher sE-selectin level and slightly higher systolic blood pressure, which in time could contribute to a greater cardiovascular risk. The exact cause and, hence, clinical consequences of the higher eGFR in HFI patients, deserves further study.</p

Quality of life of adult patients with hereditary fructose intolerance

Background: Although patients with hereditary fructose intolerance (HFI) generally have a good prognosis on a fructose-restricted diet, relatively little is known about their quality of life. The aim of this study was to investigate the quality of life in adult patients with HFI in comparison to patients with dietary-treated, classical phenylketonuria (PKU). Methods: Patients with HFI and patients with classical PKU were recruited from the adult metabolic centers in The Netherlands and Belgium and via social media. Patients were asked to fill out the 36-item Short Form Health survey (SF-36) and a modified PKU Quality Of Life (PKU-QoL) questionnaire. Results: Patients with HFI (n = 19) did not report any restrictions in their health-related quality of life, except for vitality and general mental health, which were scored more unfavorable compared to patients with PKU (n = 19) (p &lt; 0.05, adjusted for level of education and country of origin). The results from the modified PKU-QoL demonstrated a statistically significantly greater impact of the disease in the social domain in HFI. A substantial proportion of both HFI and PKU patients (21%) reported a great to severe emotional impact of their disease. Finally, patients with HFI experienced statistically significantly less food temptations, less guilt if dietary restrictions not followed, and less overall difficulty following dietary restrictions. Conclusions: Although patients with HFI showed to have a generally good quality of life, they scored lower on vitality and general mental health, and reported a greater social impact of the disease. These aspects deserve further study and clinical attention

Effects of fructose added to an oral glucose tolerance test on plasma glucose excursions in healthy adults

Background and objective: Previous experimental studies have shown that fructose interacts with glucose metabolism by increasing hepatic glucose uptake. However, human studies investigating the effects of small (‘catalytic’) amounts of fructose, added to an oral glucose load, on plasma glucose levels remain inconclusive. The aim of this study, therefore, was to repeat and extend these previous studies by examining the plasma glucose response during a 75 g oral glucose tolerance test (OGTT) with the addition of different doses of fructose. Methods: Healthy adults (n = 13) received an OGTT without addition of fructose and OGTTs with addition of different doses of fructose (1, 2, 5, 7.5 and 15 g) in a random order, on six separate occasions. Plasma glucose levels were measured every 15 min for 120 min during the study. Findings: The plasma glucose incremental area under the curve (iAUC) of the OGTT without addition of fructose was not significantly different from any OGTT with fructose (p ≥ 0.2 for all fructose doses). Similar results were observed when these data were clustered with data from a similar, previous study (pooled mean difference: 10.6; 95%CI: 45.0; 23.8 for plasma glucose iAUC of the OGTT without addition of fructose versus an OGTT with 5 g fructose; fixed-effect meta-analysis, n = 38). Of interest, serum fructose increased from 4.8 μmol/L (interquartile range: 4.1–5.9) at baseline to 5.3 μmol/L (interquartile range: 4.8–7.5) at T = 60 min during an OGTT without addition of fructose (p = 0.002). Conclusion: Low doses of fructose added to an OGTT do not affect plasma glucose levels in healthy adults. The role of endogenous fructose production, as a potential explanation of these null-findings, deserves further investigation

Thiazolidinediones and Glucagon-Like Peptide-1 Receptor Agonists and the Risk of Nonalcoholic Fatty Liver Disease: A Cohort Study

Background and Aims: Thiazolidinediones (TZDs) and glucagon-like peptide-1 (GLP-1) receptor agonists are potential pharmacological treatment options for patients at risk of NAFLD. Therefore, we examined the association between the risk of NAFLD and the use of TZDs and GLP-1 receptor agonists compared with the use of sulfonylureas (SUs) and insulins. Additionally, we calculated the incidence of HCC in users of TZDs and GLP-1 receptor agonists. Approach and Results: We conducted a population-based cohort study using primary care data from the Clinical Practice Research Datalink database (2007-2018). All patients aged ≥18 with a prescription of an oral glucose-lowering agent or GLP-1 receptor agonist were included. The first prescription defined the start of follow-up. The primary outcome was a new diagnosis of NAFLD. Cox proportional hazards regression was used to estimate HRs and 95% CIs of the primary outcome. Incidence rates of HCC were determined per 1,000 person-years for all exposures. The study identified 207,367 adults with a prescription for a glucose-lowering agent. The risk of NAFLD was lower in patients prescribed a TZD than in those prescribed an SU (adjusted HR [aHR], 0.32; 95% CI, 0.20-0.51). No difference in risk of NAFLD was observed comparing GLP-1 receptor agonist use with insulin use (aHR, 1.22; 95% CI, 0.91-1.63). Conclusions: Results of our study endorse the use of TZDs for selected patients at risk of NAFLD but do not support previous findings regarding the beneficial effect of GLP-1 receptor agonists. The low number of events in several subgroups may affect the generalizability of the current findings

High childhood serum triglyceride concentrations associate with hepatocellular adenoma development in patients with glycogen storage disease type Ia

Background & Aims: Glycogen storage disease type Ia (GSDIa) is an inborn error of carbohydrate metabolism caused by pathogenic variants in the glucose-6-phosphatase catalytic subunit 1 (G6PC1) gene and is associated with hepatocellular adenoma (HCA) formation. Data on risk factors for HCA occurrence in GSDIa are scarce. We investigated HCA development in relation to sex, G6PC1 genotype, and serum triglyceride concentration (TG). Methods: An observational study of patients with genetically confirmed GSDIa ≥12 years was performed. Patients were categorised for sex; presence of 2, 1, or 0 predicted severe G6PC1 variant (PSV); and median TG during childhood (5.65 mmol/L was associated with HCA development at younger age, compared with patients with childhood TG 5.65 mmol/L as an independent risk factor for HCA development (hazard ratio [HR] 6.0; 95% CI 1.2–29.8; p = 0.028). Conclusions: In patients with GSDIa, high childhood TG was associated with an increased risk of HCA, and earlier onset of HCA development, independent of sex-associated hypertriglyceridaemia, and G6PC1 genotype. Lay summary: Glycogen storage disease type Ia (GSDIa) is a rare, inherited metabolic disease that can be complicated by liver tumours (hepatocellular adenomas), which in turn may cause bleeding or progress to liver cancer. Risk factors associated with hepatocellular adenoma formation in patients with GSDIa are largely unknown. In our study, we found that high serum triglyceride concentrations during childhood, but not specific genetic variants, were associated with increased risk of hepatocellular adenoma diagnosis later in life