Insight into the genetic architecture of back pain and its risk factors from a study of 509,000 individuals.

Back pain (BP) is a common condition of major social importance and poorly understood pathogenesis. Combining data from the UK Biobank and CHARGE consortium cohorts allowed us to perform a very large genome-wide association study (total N = 509,070) and examine the genetic correlation and pleiotropy between BP and its clinical and psychosocial risk factors. We identified and replicated 3 BP-associated loci, including one novel region implicating SPOCK2/CHST3 genes. We provide evidence for pleiotropic effects of genetic factors underlying BP, height, and intervertebral disk problems. We also identified independent genetic correlations between BP and depression symptoms, neuroticism, sleep disturbance, overweight, and smoking. A significant enrichment for genes involved in the central nervous system and skeletal tissue development was observed. The study of pleiotropy and genetic correlations, supported by the pathway analysis, suggests at least 2 strong molecular axes of BP genesis, one related to structural/anatomical factors such as intervertebral disk problems and anthropometrics, and another related to the psychological component of pain perception and pain processing. These findings corroborate with the current biopsychosocial model as a paradigm for BP. Overall, the results demonstrate BP to have an extremely complex genetic architecture that overlaps with the genetic predisposition to its biopsychosocial risk factors. The work sheds light on pathways of relevance in the prevention and management of low BP.

Plasma N-glycome composition associates with chronic low back pain.

BACKGROUND: Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease. METHODS: Plasma samples of 1128 CLBP patients and 760 healthy controls were collected in clinical centers in Italy, Belgium and Croatia and used for N-glycosylation profiling by hydrophilic interaction ultra-performance liquid chromatography (HILIC-UPLC) after N-glycans release, fluorescent labeling and clean-up. Observed N-glycosylation profiles have been compared with a cohort of 126 patients with acute inflammation that underwent abdominal surgery. RESULTS: We have found a statistically significant increase in the relative amount of high-branched (tri-antennary and tetra-antennary) N-glycan structures on CLBP patients' plasma glycoproteins compared to healthy controls. Furthermore, relative amounts of disialylated and trisialylated glycan structures were increased, while high-mannose and glycans containing bisecting N-acetylglucosamine decreased in CLBP. CONCLUSIONS: Observed changes in CLBP on the plasma N-glycome level are consistent with N-glycosylation changes usually seen in chronic inflammation. GENERAL SIGNIFICANCE: To our knowledge, this is a first large clinical study on CLBP patients and plasma N-glycome providing a new glycomics perspective on potential disease pathology.

Identification of seven loci affecting mean telomere length and their association with disease.

Interindividual variation in mean leukocyte telomere length (LTL) is associated with cancer and several age-associated diseases. We report here a genome-wide meta-analysis of 37,684 individuals with replication of selected variants in an additional 10,739 individuals. We identified seven loci, including five new loci, associated with mean LTL (P < 5 × 10(-8)). Five of the loci contain candidate genes (TERC, TERT, NAF1, OBFC1 and RTEL1) that are known to be involved in telomere biology. Lead SNPs at two loci (TERC and TERT) associate with several cancers and other diseases, including idiopathic pulmonary fibrosis. Moreover, a genetic risk score analysis combining lead variants at all 7 loci in 22,233 coronary artery disease cases and 64,762 controls showed an association of the alleles associated with shorter LTL with increased risk of coronary artery disease (21% (95% confidence interval, 5-35%) per standard deviation in LTL, P = 0.014). Our findings support a causal role of telomere-length variation in some age-related diseases.