Aivars Lejnieks

Prof. Aivars Lejnieks

1. Department of Internal Diseases, Riga Stradins University, LV-1010 Riga, Latvia
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orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 July 2012 in New England Journal of Medicine
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Journal Article
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Aivars LejnieksAivars Lejnieks
Aivars Lejnieks
Maja Cigrovski BerkovicMaja Cigrovski Berkovic
Maja Cigrovski Berkovic
Giuseppe DerosaGiuseppe Derosa
Giuseppe Derosa
The provision of sufficient basal insulin to normalize fasting plasma glucose levels may reduce cardiovascular events, but such a possibility has not been formally tested.

26 July 2012 in New England Journal of Medicine
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Journal Article
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Aivars LejnieksAivars Lejnieks
Aivars Lejnieks
The use of n–3 fatty acids may prevent cardiovascular events in patients with recent myocardial infarction or heart failure. Their effects in patients with (or at risk for) type 2 diabetes mellitus are unknown.


1 June 2004 in Journal of Molecular Endocrinology
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Journal Article
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MBM Baryshev
M Baryshev
ESE Sargsyan
E Sargsyan
GWG Wallin
G Wallin
Aivars LejnieksAivars Lejnieks
Aivars Lejnieks
SFS Furudate
S Furudate
SMS Mkrtchian
S Mkrtchian
The unfolded protein response (UPR) is an intracellular signaling pathway that regulates the protein folding and processing capacity of the endoplasmic reticulum (ER). The UPR is induced by the pharmacological agents that perturb ER functions but is also activated upon excessive accumulation of the mutant secretory proteins that are unable to attain correct three-dimensional structure and are thus retained in the ER. Such defects in intracellular protein transport underlie the development of a number of phenotypically diverse inherited pathologies, termed endoplasmic reticulum storage diseases (ERSD). We have studied UPR development in two similar ERSDs, human congenital goiter caused by the C1264R and C1996S mutations in the thyroglobulin (Tg) gene and non-goitrous congenital hypothyroidism in rdw dwarf rats determined by the G2320R Tg mutation. In both cases, these mutations rendered Tg incapable of leaving the ER. A major ER chaperone immunoglobulin-binding protein (BiP), and a novel putative escort chaperone endoplasmic reticulum protein 29 KDa (ERp29) were found to be associated with Tg, which might be interpreted as the contribution of the quality control machinery to the previously shown retention of Tg in the ER. We have extended our earlier observations of ER chaperone induction with the identification of the additional ER (ERp29, ERp72, calreticulin, protein disulfide isomerase (PDI)), cytoplasmic (heat shock protein (HSP)70, HSP90) and mitochondrial (mtHSP70) upregulated chaperones and folding enzymes. Activation of the transcriptional arm of UPR, as judged by the appearance of the spliced (active) form of X-box binding protein (XBP1) and processed activating transcription factor 6 (ATF6) transcription factors was suggested to contribute to the overexpression of the ER chaperones. The processing of ATF6 was observed in both human and rat tissues with Tg mutations. Whereas, in human tissues, weak splicing of XBP1 mRNA was detected only in the C1264R mutant, all rat thyroids including wild-type contained significant amounts of the spliced form of XBP1 as opposed to human liver and rat brain tissues, implying the existence of a previously unknown tissue-specific regulation of XBP1 processing.

18 January 2006 in European Journal of Human Genetics
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VMVitolds Mackevics
Vitolds Mackevics
IHIris M Heid
Iris M Heid
SWStefanie A Wagner
Stefanie A Wagner
PCPaula Cip
Paula Cip
HDHildegard Doppelmayr
Hildegard Doppelmayr
BPBernhard Paulweber
Bernhard Paulweber
Low concentrations of adiponectin, the protein product of the APM1 gene, have been reported to be associated with obesity and insulin resistance. However, contrasting results have been described on the genetic variability in APM1 and characteristics of the metabolic syndrome and adiponectin serum concentrations. In the present study, we investigated the association of the two most well-known SNPs of APM1 (+45T>G and +276G>T) and their haplotypes, with serum adiponectin concentrations, metabolic parameters and intima-media thickness of the carotid arteries in 1745 well-phenotyped asymptomatic unrelated Caucasian subjects of the SAPHIR cohort. The common T-allele (88.5%) of SNP +45T>G and the common G-allele (70.5%) of SNP +276G>T were associated with significantly lower serum adiponectin levels (P=0.0008 and P=0.00005, respectively). The most frequent haplotype TG (59.0%) defined by both loci showed a strong association with lower serum adiponectin concentrations (P=0.000000002). A clear effect per copy of the respective haplotype was observed. This association was most pronounced in lean and insulin-sensitive subjects. The two less common haplotypes TT (29.5%) and GG (11.5%) were associated with higher serum adiponectin levels in a dose-dependent association. Interestingly, no significant association between the adiponectin 45–276 haplotypes and the majority of parameters of the metabolic syndrome or intima-media thickness of the carotid arteries was found in our study. In summary, we replicated a strong association of the adiponectin 45–276 genotypes and haplotypes with adiponectin levels in healthy Caucasians. However, we could not confirm an association of this gene locus with metabolic parameters of the insulin resistance syndrome.

17 December 2015 in Diabetes Care
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Aivars LejnieksAivars Lejnieks
Aivars Lejnieks
OBJECTIVE: The Outcome Reduction With Initial Glargine Intervention (ORIGIN) trial reported neutral effects of insulin glargine on cardiovascular outcomes and cancers and reduced incident diabetes in high–cardiovascular risk adults with dysglycemia after 6.2 years of active treatment. Omega-3 fatty acids had neutral effects on cardiovascular outcomes. The ORIGIN and Legacy Effects (ORIGINALE) study measured posttrial effects of these interventions during an additional 2.7 years. RESEARCH DESIGN AND METHODS: Surviving ORIGIN participants attended up to two additional visits. The hazard of clinical outcomes during the entire follow-up period from randomization was calculated. RESULTS: Of 12,537 participants randomized, posttrial data were analyzed for 4,718 originally allocated to insulin glargine (2,351) versus standard care (2,367), and 4,771 originally allocated to omega-3 fatty acid supplements (2,368) versus placebo (2,403). Posttrial, small differences in median HbA1c persisted (glargine 6.6% [49 mmol/mol], standard care 6.7% [50 mmol/mol], P = 0.025). From randomization to the end of posttrial follow-up, no differences were found between the glargine and standard care groups in myocardial infarction, stroke, or cardiovascular death (1,185 vs. 1,165 events; hazard ratio 1.01 [95% CI 0.94–1.10]; P = 0.72); myocardial infarction, stroke, cardiovascular death, revascularization, or hospitalization for heart failure (1,958 vs. 1,910 events; 1.03 [0.97–1.10]; P = 0.38); or any cancer (524 vs. 529 events; 0.99 [0.88–1.12]; P = 0.91) or between omega-3 and placebo groups in cardiovascular death (688 vs. 700; 0.98 [0.88–1.09]; P = 0.68) or other outcomes. CONCLUSIONS: During >6 years of treatment followed by >2.5 years of observation, insulin glargine had neutral effects on health outcomes and salutary effects on metabolic control, whereas omega-3 fatty acid supplementation had no effect.