0000000000584579
AUTHOR
Jussi Pihlajamäki
showing 21 related works from this author
Rare <i>Atg7</i>&nbsp;Genetic Variants Predispose to Severe Fatty Liver Disease
2021
Background&Aims: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease and has a strong heritable component. The aim of this study was to identify new genes involved in NAFLD pathogenesis. Methods: We examined rare variants captured by whole-exome sequencing in individuals with severe fibrosis or hepatocellular carcinoma due to NAFLD (severe NAFLD, n=301) after variant prioritization. We replicated the results in the UK Biobank and the Liver biopsy cohort (n=2268). Results: We observed an enrichment of the p.P426L variant (rs143545741 C>T; OR=7.2, 2.3-17.3; p C; MAF=0.060 vs. 0.035; OR=1.7, 1.2-2.5; p=0.003). In the UK Biobank cohort, the p.V471A variant wa…
Protein phosphatase 1 regulatory subunit 3B gene variation protects against hepatic fat accumulation and fibrosis in individuals at high risk of nona…
2018
Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver damage and has a strong genetic component. The rs4841132 G>A variant, modulating the expression of protein phosphatase 1 regulatory subunit 3B (PPP1R3B), which is involved in glycogen synthesis, has been reported to reduce the risk of NAFLD but at the same time may favor liver disease by facilitating glycogen accumulation. The aim of this study was to assess the impact of rs4841132 on development of histologic steatosis and fibrosis in 1,388 European individuals in a liver biopsy cohort, on NAFLD hepatocellular carcinoma in a cross-sectional Italian cohort (n = 132 cases), and on liver disease at the population level in the …
The effectiveness and applicability of different lifestyle interventions for enhancing wellbeing : the study design for a randomized controlled trial…
2014
Background: Obesity and stress are among the most common lifestyle-related health problems. Most of the current disease prevention and management models are not satisfactorily cost-effective and hardly reach those who need them the most. Therefore, novel evidence-based controlled interventions are necessary to evaluate models for prevention and treatment based on self-management. This randomized controlled trial examines the effectiveness, applicability, and acceptability of different lifestyle interventions with individuals having symptoms of metabolic syndrome and psychological distress. The offered interventions are based on cognitive behavioral approaches, and are designed for enhancing…
PCSK9 rs11591147 R46L loss-of-function variant protects against liver damage in individuals with NAFLD
2020
Background and Aims: The proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis, and its inhibition represents an effective therapy to lower low-density lipoprotein cholesterol (LDL-C) levels. In this study, we examined the impact of the PCSK9 rs11591147 loss-of-function (LOF) variant on liver damage in a multicenter collection of patients at risk of nonalcoholic steatohepatitis (NASH), in clinical samples and experimental models. Methods: We considered 1874 consecutive individuals at risk of NASH as determined by histology. The SNP rs11591147, encoding for the p.R46L variant of PCSK9, was genotyped by TaqMan assays. We also evaluated 1) PCSK9 mRNA…
<i>NR1H4</i> rs35724 G&gt;C Variant Modulates Liver Damage in Nonalcoholic Fatty Liver Disease
2020
Background and Aims: Farnesoid X receptor (FXR) plays a key role in bile acid and lipid homeostasis. Experimental evidence suggests that it can modulate liver damage related to nonalcoholic fatty liver disease (NAFLD). We examined the impact of the NR1H4 rs35724 variant, encoding for FXR, on liver damage in a large cohort of patients at risk of steatohepatitis. Methods: We considered 2,660 consecutive individuals at risk of steatohepatitis with liver histology. The rs35724 G>C polymorphisms was genotyped by TaqMan assays. Gene expression was evaluated by RNASeq in a subset of patients (n=124). Results: The NR1H4 rs35724 variant was protective against severity of steatosis (OR 0.89, 95% C.I.…
Genetic variants in the MTHFR are not associated with fatty liver disease.
2020
The common missense sequence variants of methylenetetrahydrofolate reductase (MTHFR), rs1801131 (c.A1298C) and rs1801133 (c.C677T), favour the development of hyperhomocysteinemia and diminished DNA methylation. Previous studies, carried out in small series and with suboptimal characterization of the hepatic phenotype, tested the association of these genetic variants with fatty liver disease (FLD), with conflicting results. Here, we assessed the association of rs1801131 and rs1801133 with hepatic phenotype in the Liver Biopsy Cross-Sectional Cohort, a large cohort (n=1375 from Italy and 411 from Finland) of European individuals with suspect FLD associated with dysmetabolism. A total of 1786 …
Exome-Wide Association Study on Alanine Aminotransferase Identifies Sequence Variants in the GPAM and APOE Associated With Fatty Liver Disease.
2021
BACKGROUND & AIMS: Fatty liver disease (FLD) is a growing epidemic that is expected to be the leading cause of end-stage liver disease within the next decade. Both environmental and genetic factors contribute to the susceptibility of FLD. Several genetic variants contributing to FLD have been identified in exome-wide association studies. However, there is still a missing hereditability indicating that other genetic variants are yet to be discovered. METHODS: To find genes involved in FLD, we first examined the association of missense and nonsense variants with alanine amino transferase at an exome-wide level in 425,671 participants from the UK Biobank. We then validated genetic variants wit…
High perceived stress is associated with unfavorable eating behavior in overweight and obese Finns of working age
2016
Stress-related eating may be a potential factor in the obesity epidemic. Rather little is known about how stress associates with eating behavior and food intake in overweight individuals in a free-living situation. Thus, the present study aims to investigate this question in psychologically distressed overweight and obese working-aged Finns. The study is a cross-sectional baseline analysis of a randomized controlled trial. Of the 339 study participants, those with all the needed data available (n = 297, 84% females) were included. The mean age was 48.9 y (SD = 7.6) and mean body mass index 31.3 kg/m(2) (SD = 3.0). Perceived stress and eating behavior were assessed by self-reported questionn…
The MBOAT7-TMC4 Variant rs641738 Increases Risk of Nonalcoholic Fatty Liver Disease in Individuals of European Descent
2016
Background & Aims Nonalcoholic fatty liver disease (NAFLD) is a leading cause of liver damage and is characterized by steatosis. Genetic factors increase risk for progressive NAFLD. A genome-wide association study showed that the rs641738 C>T variant in the locus that contains the membrane bound O-acyltransferase domain-containing 7 gene (MBOAT7, also called LPIAT1) and transmembrane channel-like 4 gene (TMC4) increased the risk for cirrhosis in alcohol abusers. We investigated whether the MBOAT7-TMC4 is a susceptibility locus for the development and progression of NAFLD. Methods We genotyped rs641738 in DNA collected from 3854 participants from the Dallas Heart Study (a multi-ethnic…
Prevalence and Risk Factors of Significant Fibrosis in Patients With Nonalcoholic Fatty Liver Without Steatohepatitis
2019
In patients with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH) is a risk factor for the development of fibrosis. However, fibrosis has been observed in livers of patients without NASH. We aimed to estimate the prevalence of fibrosis in patients without NASH and risk factors for fibrosis.We analyzed data from 1738 subjects (44.9% with severe obesity) in a cross-sectional liver biopsy cohort enrolled at referral centers in Italy and Finland. Biopsy specimens were analyzed histologically by a blinded pathologist at each center, and a diagnosis of NASH was made based on steatosis (≥5% of hepatocytes), hepatocellular ballooning, and lobular inflammation. We also c…
Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease
2023
Background and aims: Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. Methods: We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholi…
Epigenetic markers associated with metformin response and intolerance in drug-naïve patients with type 2 diabetes
2020
Metformin is the first-line pharmacotherapy for managing type 2 diabetes (T2D). However, many patients with T2D do not respond to or tolerate metformin well. Currently, there are no phenotypes that successfully predict glycemic response to, or tolerance of, metformin. We explored whether blood-based epigenetic markers could discriminate metformin response and tolerance by analyzing genome-wide DNA methylation in drug-naïve patients with T2D at the time of their diagnosis. DNA methylation of 11 and 4 sites differed between glycemic responders/nonresponders and metformin-tolerant/intolerant patients, respectively, in discovery and replication cohorts. Greater methylation at these sites associ…
Statin use and non-alcoholic steatohepatitis in at risk individuals.
2015
Background & Aims Excess hepatic free cholesterol contributes to the pathogenesis of non-alcoholic steatohepatitis, and statins reduce cholesterol synthesis. Aim of this study was to assess whether statin use is associated with histological liver damage related to steatohepatitis. Methods The relationship between statin use, genetic risk factors, and liver damage was assessed in a multi-center cohort of 1201 European individuals, who underwent liver biopsy for suspected non-alcoholic steatohepatitis. Results Statin use was recorded in 107 subjects, and was associated with protection from steatosis, NASH, and fibrosis stage F2-F4, in a dose-dependent manner (adjusted p <0.05 for all).…
The effects of acceptance and commitment therapy on eating behavior and diet delivered through face-to-face contact and a mobile app: a randomized co…
2018
Background Internal motivation and good psychological capabilities are important factors in successful eating-related behavior change. Thus, we investigated whether general acceptance and commitment therapy (ACT) affects reported eating behavior and diet quality and whether baseline perceived stress moderates the intervention effects. Methods Secondary analysis of unblinded randomized controlled trial in three Finnish cities. Working-aged adults with psychological distress and overweight or obesity in three parallel groups: (1) ACT-based Face-to-face (n = 70; six group sessions led by a psychologist), (2) ACT-based Mobile (n = 78; one group session and mobile app), and (3) Control (n = 71; …
<i>PCSK9</i> rs11591147 R46L Loss-of-Function Variant Protects Against Liver Damage in Individuals with NAFLD
2020
Background and Aims: The proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis, and its inhibition represents an effective therapy to lower LDL-C levels. In this study, we examined the impact of PCSK9 rs11591147 loss-of-function (LOF) variant on liver damage in a multicenter collection of patients at risk of nonalcoholic steatohepatitis (NASH), in clinical samples and experimental models. Methods: We considered 1,874 consecutive individuals at risk of NASH as determined by histology. The SNP rs11591147, encoding for the p.R46L variant of PCSK9, was genotyped by TaqMan assays. We also evaluated 1) PCSK9 mRNA hepatic expression in human liver, and 2…
NR1H4 rs35724 G>C variant modulates liver damage in nonalcoholic fatty liver disease
2021
Background and Aims: Farnesoid X receptor (FXR) plays a key role in bile acid and lipid homeostasis. Experimental evidence suggests that it can modulate liver damage related to nonalcoholic fatty liver disease (NAFLD). We examined the impact of the NR1H4 rs35724 G>C, encoding for FXR, on liver damage in a large cohort of patients at risk of steatohepatitis. Methods: We considered 2,660 consecutive individuals at risk of steatohepatitis with liver histology. The rs35724 G>C polymorphisms were genotyped by TaqMan assays. Gene expression was evaluated by RNASeq in a subset of patients (n = 124). Results: The NR1H4 rs35724 CC genotype, after adjusting for clinic-metabolic and genetic conf…
The Effects of Acceptance and Commitment Therapy (ACT) Intervention on Inflammation and Stress Biomarkers : a Randomized Controlled Trial
2020
Abstract Background Psychological processes can be manifested in physiological health. We investigated whether acceptance and commitment therapy (ACT), targeted on psychological flexibility (PF), influences inflammation and stress biomarkers among working-age adults with psychological distress and overweight/obesity. Method Participants were randomized into three parallel groups: (1) ACT-based face-to-face (n = 65; six group sessions led by a psychologist), (2) ACT-based mobile (n = 73; one group session and mobile app), and (3) control (n = 66; only the measurements). Systemic inflammation and stress markers were analyzed at baseline, at 10 weeks after the baseline (post-intervention), and…
Transmembrane 6 Superfamily Member 2 Gene Variant Disentangles Nonalcoholic Steatohepatitis From Cardiovascular Disease
2015
Excess hepatic storage of triglycerides is considered a benign condition, but nonalcoholic steatohepatitis (NASH) may progress to fibrosis and promote atherosclerosis. Carriers of the TM6SF2 E167K variant have fatty liver as a result of reduced secretion of very-low-density lipoproteins (VLDLs). As a result, they have lower circulating lipids and reduced risk of myocardial infarction. In this study, we aimed to assess whether TM6SF2 E167K affects liver damage and cardiovascular outcomes in subjects at risk of NASH. Liver damage was evaluated in 1,201 patients who underwent liver biopsy for suspected NASH; 427 were evaluated for carotid atherosclerosis. Cardiovascular outcomes were assessed …
PSD3 downregulation confers protection against fatty liver disease
2022
Fatty liver disease (FLD) is a growing health issue with burdening unmet clinical needs. FLD has a genetic component but, despite the common variants already identified, there is still a missing heritability component. Using a candidate gene approach, we identify a locus (rs71519934) at the Pleckstrin and Sec7 domain-containing 3 (PSD3) gene resulting in a leucine to threonine substitution at position 186 of the protein (L186T) that reduces susceptibility to the entire spectrum of FLD in individuals at risk. PSD3 downregulation by short interfering RNA reduces intracellular lipid content in primary human hepatocytes cultured in two and three dimensions, and in human and rodent hepatoma cell…
PCSK7 gene variation bridges atherogenic dyslipidemia with hepatic inflammation in NAFLD patients
2019
Dyslipidemia and altered iron metabolism are typical features of nonalcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7) gene variation has been associated with circulating lipids and liver damage during iron overload. The aim of this study was to examine the impact of the PCSK7 rs236918 variant on NAFLDrelated traits in 1,801 individuals from the Liver Biopsy Cohort (LBC), 500,000 from the UK Biobank Cohort (UKBBC), and 4,580 from the Dallas Heart Study (DHS). The minor PCSK7 rs236918 C allele was associated with higher triglycerides, aminotransferases, and hepatic inflammation in the LBC (P < 0.05) and with hypercholesterolemia and liver disease …
Sleep-time physiological recovery is associated with eating habits in distressed working-age Finns with overweight: secondary analysis of a randomise…
2021
Background Association of physiological recovery with nutrition has scarcely been studied. We investigated whether physiological recovery during sleep relates to eating habits, i.e., eating behaviour and diet quality. Methods Cross-sectional baseline analysis of psychologically distressed adults with overweight (N = 252) participating in a lifestyle intervention study in three Finnish cities. Recovery measures were based on sleep-time heart rate variability (HRV) measured for 3 consecutive nights. Measures derived from HRV were 1) RMSSD (Root Mean Square of the Successive Differences) indicating the parasympathetic activation of the autonomic nervous system and 2) Stress Balance (SB) indica…