Markku J. Nissinen

Parenteral plant sterols and intestinal failure-associated liver disease in neonates.

Objectives: We prospectively evaluated incidence of prolonged (>28 days) parenteral nutrition (PN), associated complications, and significance of parenteral plant sterols (PS) in neonatal intestinal failure–associated liver disease (IFALD) compared with children. Methods: We recruited 28 neonates (mean age 50 days, range 28–126) and 11 children (6.9 y, 2.1–16.6) in all of Finland. Patients underwent repeated measurements of serum cholesterol, noncholesterol sterols, including PS, cholestanol and cholesterol precursors, and liver biochemistry during and 1 month after discontinuation of PN. Healthy matched neonates (n = 10) and children (n = 22) served as controls. Results: IFALD occurred more frequently among neonates (63%) than children (27%; P < 0.05). Ratios of serum PS, including stigmasterol, sitosterol, avenasterol, and campesterol, and total PS were increased among neonates compared with healthy controls and children on PN by 2- to 22- and 2- to 5-fold (P < 0.005), respectively. Neonates with IFALD had significantly higher ratios of serum PS and cholestanol compared with neonates without IFALD (P < 0.05). Total duration of PN associated with serum cholestanol, stigmasterol, avenasterol, alanine aminotransferase, and aspartate aminotransferase (r = 0.472–0.636, P < 0.05). Cholestanol and individual serum PS, excluding campesterol, reflected direct bilirubin (r = 0.529–0.688, P < 0.05). IFALD persisted after discontinuation of PN in 25% of neonates with 4.2- and 2.2-times higher ratios of serum stigmasterol and cholestanol compared with neonates without IFALD (P < 0.05). Conclusions: Frequent occurrence of IFALD among neonates on PN displays an association to duration of PN and markedly increased serum PS, especially stigmasterol, in comparison to healthy neonates and children on PN. Striking accumulation of parenteral PS may contribute to IFALD among neonates.

The role of serum non-cholesterol sterols as surrogate markers of absolute cholesterol synthesis and absorption.

AIMS To study the whole-body cholesterol metabolism in man, cholesterol synthesis and absorption need to be measured. Because of the complicated methods of the measurements, new approaches were developed including the analysis of serum non-cholesterol sterols. In current lipidologic papers and even in intervention studies, serum non-cholesterol sterols are frequently used as surrogate markers of cholesterol metabolism without any validation to the absolute metabolic variables. The present review compares serum non-cholesterol sterols with absolute measurements of cholesterol synthesis and absorption in published papers to find out whether the serum markers are valid indicators of cholesterol metabolism in various conditions. DATA SYNTHESIS During statin treatment, during interventions of dietary fat, and in type 2 diabetes the relative and absolute variables of cholesterol synthesis and absorption were frequently but not constantly correlated with each other. In some occasions, especially in subjects with apolipoprotein E3/4 and E4/4 phenotypes, the relative metabolic markers were even more sensitive than the absolute ones to reflect changes in cholesterol metabolism during dietary interventions. Even in general population at very high absorption the homeostasis of cholesterol metabolism is disturbed damaging the validity of the serum markers. CONCLUSIONS It is worth using several instead of only one precursor and absorption sterol marker for making conclusions of altered synthesis or absorption of cholesterol, and even then the presence of at least some absolute measurement is valuable. During consumption of plant sterol-enriched diets and in situations of interfered cholesterol homeostasis the relative markers do not adequately reflect cholesterol metabolism. Accordingly, the validity of the relative markers of cholesterol metabolism should not be considered as self-evident.

Achievement of deep remission during scheduled maintenance therapy with TNFα-blocking agents in IBD

BACKGROUND AND AIMS Deep remission, meaning clinical remission with mucosal healing (MH), with anti-tumor necrosis factor-alpha (TNF-α) agents is a new target for therapy in inflammatory bowel disease (IBD). Our aim was to study how often patients on TNF-α blocking therapy actually achieve deep remission. METHODS The total of 252 IBD patients retrospectively included (183 Crohns disease (CD), 62 ulcerative colitis (CU) or 7 inflammatory bowel disease unclassified-type colitis (IBDU)) received TNFα-antagonists (177 infliximab, 75 adalimumab) for at least 11 months and underwent ileocolonoscopy. We reviewed endoscopic and histological findings, clinical symptoms, C-reactive protein (CRP), and fecal calprotectin (FC) levels, and data on TNF-α blocking therapy. Defining deep remission as no clinical symptoms with endoscopic remission (the simple endoscopic score for Crohns disease, SES-CD 0-2 or Mayo endoscopic subscore 0-1). RESULTS Of the 252 patients, 168 (67%) were in clinical remission and 122 (48%) in deep remission after a median of 23 months of maintenance therapy. Of the 183 CD patients, 117 (64%) reached clinical remission and 79 (43%) deep remission. Of the UC patients, 52 (75%) were in clinical remission and 43 (62%) in deep remission. The majority of patients in deep remission (n=99, 81%) also had histologically inactive disease. Both median CRP and FC levels were significantly lower in patients with deep remission. CONCLUSION Reassuringly, half of the IBD patients on the TNFα-blocking maintenance therapy achieved deep remission. The majority of patients in deep remission also achieved histological remission.

Does Fecal Calprotectin Predict Short-Term Relapse After Stopping Tnfα-Blocking Agents In Inflammatory Bowel Disease Patients In Deep Remission?

BACKGROUND AND AIMS This prospective multicenter study examined whether elevated fecal calprotec tin (FC) concentrations after stopping TNFα-blocking therapy can predict clinical or endoscopic relapse. In addition, we evaluated the impact of histological remission on the relapse risk. METHODS We enrolled inflammatory bowel disease (IBD) patients who were in clinical, endoscopic, and FC-based (< 100 μg/g) remission after a minimum 11 months of TNFα-blocking therapy. The patients were followed-up for 12 months after the discontinuation of TNFα-blocking therapy. FC was collected monthly for the first 6 months and thereafter every second month. Ileocolonoscopy was performed at inclusion, at 4 months, at the study end, and at the time of clinical relapse. RESULTS Of 52 enrolled patients, 49 (16 Crohns disease, 33 ulcerative colitis/IBD unclassified) provided the stool samples requested and comprised the study group. During the follow-up, 15/49 (31%) relapsed, whereas 34 (69%) remained in remission. Patients relapsing showed constantly elevated FC levels for a median of 94 (13-317) days before the relapse. Significant increase in median FC levels was seen 2 (p = 0.0014), 4 (p = 0.0056), and 6 (p = 0.0029) months before endoscopic relapse. Constantly normal FC concentrations during the follow-up were highly predictive for clinical and endoscopic remission. Normal FC concentrations in patients with remission were associated with histological remission. CONCLUSION FC seems to increase and remain elevated before clinical or endoscopic relapse, suggesting that it can be used as a surrogate marker for predicting and identifying patients requiring close follow-up in clinical practice.

The effect of a very high daily plant stanol ester intake on serum lipids, carotenoids, and fat-soluble vitamins

BACKGROUND & AIMS Intake of 2-3 g/d of plant stanols as esters lowers LDL cholesterol level, but there is no information about the efficacy and safety of a respective very high daily intake. We studied the effects of 8.8 g/d of plant stanols as esters on serum lipids and safety variables in subjects with mild to moderate hypercholesterolemia. METHODS In a randomized, double-blind, placebo-controlled study the intervention (n=25) and control (n=24) groups consumed spread and drink enriched or not with plant stanol esters for 10 weeks. RESULTS Plant stanols reduced serum total and LDL cholesterol concentrations by 12.8 and 17.3% from baseline and by 12.0 and 17.1% from controls (P<0.01 for all). Liver enzymes, markers of hemolysis, and blood cells were unchanged. Serum vitamins A, D, and gamma-tocopherol concentrations, and the ratios of alpha-tocopherol to cholesterol were unchanged. Serum beta-carotene concentrations decreased significantly from baseline and were different from controls even when adjusted for cholesterol. Serum alpha-carotene concentration and alpha-carotene/cholesterol ratio were not different from controls. CONCLUSIONS High intake of plant stanols reduced LDL cholesterol values without any other side effects than reduction of serum beta-carotene concentration. However, the end product, serum vitamin A levels, were unchanged. The results suggest that plant stanol ester intake can be increased to induce a greater cholesterol lowering effect.

Responses of surrogate markers of cholesterol absorption and synthesis to changes in cholesterol metabolism during various amounts of fat and cholesterol feeding among healthy men

Serum ratios to cholesterol of lathosterol, and of cholestanol, campesterol and sitosterol measure respective relative cholesterol synthesis and absorption, but their clinical applicability is not known in evaluation of cholesterol metabolism under different dietary conditions. We compared relative synthesis and absorption of cholesterol to the respective absolute ones in healthy male volunteers (n 29) on four subsequent diets: baseline home (HD), low-cholesterol low-fat (LCLF), high-cholesterol low-fat (HCLF) and low-cholesterol high-fat (LCHF). Serum lipids, lipoproteins, sterols, fractional cholesterol absorption and sterol synthesis were examined. HCLF and LCHF decreased fractional cholesterol absorption by approximately 23-27 % from baseline HD (P < 0.05) and increased the levels of total and LDL-cholesterol in serum from LCLF by approximately 9-14 % (P < 0.05). On HCLF, bile acid synthesis was high (P < 0.05 for each), and absolute cholesterol synthesis tended to be higher than on HD and LCHF (NS). Relative synthesis was positively associated with absolute cholesterol synthesis, but inversely with relative absorption during each diet (P < 0.05). The relative absorption markers were interrelated in each diet, and were also associated with fractional absorption of cholesterol in each diet but HD. In conclusion, relative markers of cholesterol absorption and synthesis reflect changes in cholesterol metabolism despite the amount of dietary fat and cholesterol consumed, but their validity with this respect is strengthened by controlled diets in metabolic studies. Additions of cholesterol and fat to a diet low in fat and cholesterol cause practically equal changes in the serum lipid profiles, whereas synthesis of cholesterol (NS) and bile acids (P < 0.05) were higher with the high-cholesterol feeding.

Multiple sites of L-histidine decarboxylase expression in mouse suggest novel developmental functions for histamine

Histamine mediates many types of physiologic signals in multicellular organisms. To clarify the developmental role of histamine, we have examined the developmental expression of L‐histidine decarboxylase (HDC) mRNA and the production of histamine during mouse development. The predominant expression of HDC in mouse development was seen in mast cells. The HDC expression was evident from embryonal day 13 (Ed13) until birth, and the mast cells were seen in most peripheral tissues. Several novel sites with a prominent HDC mRNA expression were revealed. In the brain, the choroid plexus showed HDC expression at Ed14 and the raphe neurons at Ed15. Close to the parturition, at Ed19, the neurons in the tuberomammillary (TM) area and the ventricular neuroepithelia also displayed a clear HDC mRNA expression and histamine immunoreactivity (HA‐ir). From Ed14 until birth, the olfactory and nasopharyngeal epithelia showed an intense HDC mRNA expression and HA‐ir. In the olfactory epithelia, the olfactory receptor neurons (ORN) were shown to have very prominent histamine immunoreactivity. The bipolar nerve cells in the epithelium extended both to the epithelial surface and into the subepithelial layers to be collected into thick nerve bundles extending caudally toward the olfactory bulbs. Also, in the nasopharynx, an extensive subepithelial network of histamine‐immunoreactive nerve fibers were seen. Furthermore, in the peripheral tissues, the degenerating mesonephros (Ed14) and the convoluted tubules in the developing kidneys (Ed15) showed HDC expression, as did the prostate gland (Ed15). In adult mouse brain, the HDC expression resembled the neuronal pattern observed in rat brain. The expression was restricted to the TM area in the ventral hypothalamus, with the main expression in the five TM subgroups called E1–E5. A distinct mouse HDC mRNA expression was also seen in the ependymal wall of the third ventricle, which has not been reported in the rat. The tissue‐ and cell‐specific expression patterns of HDC and histamine presented in this work indicate that histamine could have cell guidance or regulatory roles in development.

Effects of long-term parenteral nutrition on serum lipids, plant sterols, cholesterol metabolism, and liver histology in pediatric intestinal failure.

Background and Objective: Plant sterols (PS) in parenteral nutrition (PN) may contribute to intestinal failure–associated liver disease. We investigated interrelations between serum PS, liver function and histology, cholesterol metabolism, and characteristics of PN. Patients and Methods: Eleven patients with intestinal failure (mean age 6.3 years) receiving long-term PN were studied prospectively (mean 254 days) and underwent repeated measurements of serum lipids, noncholesterol sterols, including PS, and liver enzymes. PS contents of PN were analyzed. Liver biopsy was obtained in 8 patients. Twenty healthy children (mean age 5.7 years) served as controls. Results: Median percentage of parenteral energy of total daily energy (PN%) was 48%, including 0.9 g · kg−1 · day−1 of lipids. Respective amounts of PN sitosterol, campesterol, avenasterol, and stigmasterol were 683, 71, 57, and 45 &mgr;g · kg−1 · day−1. Median serum concentrations of sitosterol (48 vs 7.5 &mgr;mol/L, P < 0.001), avenasterol (2.9 vs 1.9, P < 0.01), stigmasterol (1.9 vs 1.2, P < 0.005), but not that of campesterol (9.8 vs 12, P = 0.22), were increased among patients in relation to controls, and correlated with PN% (r = 0.81–0.88, P < 0.005), but not with PN fat. Serum cholesterol precursors were higher in patients than in controls. Serum liver enzymes remained close to normal range. Glutamyl transferase correlated with serum PS (r = 0.61–0.62, P < 0.05). Liver fibrosis in 5 patients reflected increased serum PS (r = 0.55–0.60, P = 0.16–0.12). Conclusions: Serum PS moderately increase during olive oil–based PN, and correlate positively with PN% and glutamyl transferase. Despite well-preserved liver function, histology often revealed significant liver damage.

Applicability of non-cholesterol sterols in predicting response in cholesterol metabolism to simvastatin and fluvastatin treatment among hypercholesterolemic men

BACKGROUND AND AIMS We hypothesized that (I) certain features in cholesterol metabolism at baseline could predict a response to statins, (II) good and poor responders to statins have a differential profile of serum and fecal sterols and (III) serum non-cholesterol sterols reflect cholesterol metabolism on statins. METHODS AND RESULTS We examined serum lipids, serum and fecal cholesterol, cholesterol precursors, cholestanol and phytosterols and cholesterol metabolism among 20 hypercholesterolemic men at baseline and on 16-wk simvastatin/fluvastatin treatment. At baseline, the mean of serum cholestanol/cholesterol was 11% lower but those of lathosterol/cholesterol, lathosterol/cholestanol, desmosterol/cholesterol, desmosterol/cholestanol were 36-65% higher among good than poor responders (p<0.05 for each). On statins, reductions in ratios of serum precursor sterols and increases of absorption sterols were 1.8-2.9 times higher among good than poor responders (p<0.05 for each). In the whole study group, changes from baseline values of lathosterol/cholestanol were related to those of cholesterol and LDL-C in serum (r=+0.513 and +0.451, p=0.021 and 0.046, respectively). Serum lathosterol ratios to cholesterol, cholestanol and sitosterol consistently reflected a ratio of cholesterol synthesis (mg/d/kg)/fractional cholesterol absorption (%) (r-range +0.456 to +0.727, p<0.05 for each). CONCLUSIONS Low serum baseline ratios to cholesterol of lathosterol, cholestenol and desmosterol, but a high ratio of cholestanol predicted a poor response to statins. Good responders were characterized by more profound reductions of serum and fecal (lathosterol) precursor sterols and increases of serum absorption marker sterol ratios on statins. Serum surrogate sterol markers of cholesterol metabolism were applicable in evaluating cholesterol absorption and synthesis also on statins.

Effect of Parenteral Serum Plant Sterols on Liver Enzymes and Cholesterol Metabolism in a Patient With Short Bowel Syndrome

Hepatobiliary complications are common during parenteral nutrition. Lipid moiety in commercially available solutions contains plant sterols. It is not known whether plant sterols in parenteral nutrition interfere with hepatic function in adults. We detected how different amounts of plant sterols in parenteral nutrition solution affected serum plant sterol concentrations and liver enzymes during a 1.5-year follow-up in a patient with short bowel syndrome. Serum lipid, plant sterol, and liver enzyme levels were measured regularly during the transition from Intralipid (100% soy-based intravenous fat emulsion) to ClinOleic (an olive oil-based intravenous fat emulsion with 80% olive oil, 20% soy oil and lower plant sterols); the lipid supply was also gradually increased from 20 to 35 g/d. Plant sterols in parenteral nutrition solution and serum were measured with gas-liquid chromatography. During infusion of soy-based intravenous fat emulsion (30 g/d, total plant sterols 87 mg/d), the concentrations of sitosterol, campesterol, and stigmasterol were 4361, 1387, and 378 microg/dL, respectively, and serum liver enzyme values were >or= 2.5 times above upper limit of normal. After changing to olive oil-based intravenous fat emulsion (20-35 g/d, plant sterols 37-65 mg/d), concentrations decreased to 2148 to 2251 microg/dL for sitosterol, 569-297 microg/dL for campesterol, and 95-55 microg/dL for stigmasterol. Concomitantly, liver enzyme values decreased to 1.4 to 1.8 times above upper limit of normal at the end of follow-up. The nutrition status of the patient improved. The amount of plant sterols in lipid emulsion affects serum liver enzyme levels more than the amount of lipid.