Electronic health record reveals community-level cardiometabolic health benefits associated with 10 years of community-based participatory research

BACKGROUND

While a major goal of community-based participatory research (CBPR) is to improve community health; it is unclear how to measure longstanding success of CBPR.

OBJECTIVE

We sought to determine the impact of ongoing CBPR on cardiometabolic health of participating communities, including in people not directly participating in research.

METHODS

We used linear mixed-effects modelling with electronic medical records from 2002 to 2012 from the Yukon-Kuskokwim Health Corporation, which provides health care to all Alaska Native people in southwestern Alaska, to compare rates of change in cardiometabolic risk factors between communities that did and did not participate in ongoing CBPR beginning in 2003.

RESULTS

We analysed 1,262,035 medical records from 12,402 individuals from 10 study and 38 control communities. Blood pressure declined faster in study than in control communities: systolic blood pressure (0.04 mmHg/year; 95% confidence interval [CI]: 0.01, 0.08); diastolic blood pressure (DBP) (0.07 mmHg/year; 95% CI: 0.04, 0.09). Body mass index increased 0.04 units/year faster in study communities than in control communities (95% CI: 0.03, 0.05). More study visits were associated with faster reduction of DBP and triglyceride levels in study communities.

CONCLUSIONS

Ongoing CBPR may improve overall cardiometabolic health in communities, perhaps by increasing engagement in health and advocacy.

Imputation of class I and II HLA loci using high-density SNPs from ImmunoChip and their associations with Kawasaki disease in family-based study

Kawasaki disease (KD) is the leading cause of acquired heart disease in children in most developed countries including the United States. The etiology of KD is not known; however, epidemiological and immunological data suggest infectious or immune-related factors in the manifestation of the disease. Further, KD has several hereditary features that strongly suggest a genetic component to disease pathogenesis. Human leucocyte antigen (HLA) loci have also been reported to be associated with KD, but results have been inconsistent, in part, because of small study samples and varying linkage disequilibrium (LD) patterns observed across different ethnic groups. To maximize the informativeness of single nucleotide polymorphism (SNP) genotypes in the major histocompatibility (MHC) region, we imputed classical HLA I (A, B, C) and HLA II (DRB1, DQA1, DQB1) alleles using SNP2HLA method from genotypes of 6700 SNPs within the extended MHC region contained in the ImmunoChip among 112 White patients with KD and their biological parents from North America and tested their association with KD susceptibility using the transmission disequilibrium test. Mendelian consistency in the trios suggested high accuracy and reliability of the imputed alleles (class I = 97.5%, class II = 96.6%). While several SNPs in the MHC region were individually associated with KD susceptibility, we report over-transmission of HLA-C*15 (z = +2.19, P = 0.03) and under-transmission of HLA-B*44 (z = -2.49, P = 0.01) alleles from parents to patients with KD. HLA-B*44 has been associated with KD in other smaller studies, and both HLA-C*15 and HLA-B*44 have biological mechanisms that could potentially be involved in KD pathogenesis. Overall, inferring HLA loci within the same ethnic group, using family-based information is a powerful approach. However, studies with larger sample sizes are warranted to evaluate the correlations of the strength and directions between the SNPs in MHC region and the imputed HLA alleles with KD.

SNP screening of central MHC-identified HLA-DMB as a candidate susceptibility gene for HIV-related Kaposi's sarcoma

The major histocompatibility complex (MHC) region on chromosome 6p21.3 is suspected to host susceptibility loci for HIV-related Kaposi’s sarcoma (HIV-KS). A nested case-control study in the Multicenter AIDS Cohort Study was designed to conduct fine genetic association mapping across central MHC. Individuals co-infected with HIV-1 and HHV-8 who later developed KS were defined as cases (n=354) and were matched 1:1 with co-infected KS-free controls.

We report data for new independent MHC class II and III susceptibility loci. In particular, class II HLA-DMB emerged as a strong candidate, with the intronic variant rs6902982 A>G associated with a 4-fold increase of risk (OR= 4.09; 95% CI: 1.90–8.80; p= 0.0003). A striking multiplicative effect on the estimated risk was associated with further carriage of two non-synonymous variants, rs1800453 A>G (Asp697Gly) and rs4148880 A>G (Ile393Val), in the linked TAP1 gene (OR=10.5; 95% CI: 2.54–43.6; p=0.0012). The class III susceptibility variant is moderately associated with HIV-KS and lies within a 120 Kb-long haplotype (OR=1.52; 95% CI: 1.01–2.28; p=0.047) formed by rs7029 A>G (GPANK1 3’UTR), rs1065356 G>A (LY6G6C), rs3749953 A>G (MSH5-SAPCD1 readthrough) and rs707926 G>A (VARS). Our data suggest that antigen processing by MHC class II molecules is a target pathway in the pathogenesis of HIV-KS.

Persistent infection with neurotropic herpes viruses and cognitive impairment

BACKGROUND

Herpes virus infections can cause cognitive impairment during and after acute encephalitis. Although chronic, latent/persistent infection is considered to be relatively benign, some studies have documented cognitive impairment in exposed persons that is untraceable to encephalitis. These studies were conducted among schizophrenia (SZ) patients or older community dwellers, among whom it is difficult to control for the effects of co-morbid illness and medications. To determine whether the associations can be generalized to other groups, we examined a large sample of younger control individuals, SZ patients and their non-psychotic relatives (n=1852). Method Using multivariate models, cognitive performance was evaluated in relation to exposures to herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2) and cytomegalovirus (CMV), controlling for familial and diagnostic status and sociodemographic variables, including occupation and educational status. Composite cognitive measures were derived from nine cognitive domains using principal components of heritability (PCH). Exposure was indexed by antibodies to viral antigens.

RESULTS

PCH1, the most heritable component of cognitive performance, declines with exposure to CMV or HSV-1 regardless of case/relative/control group status (p = 1.09 × 10-5 and 0.01 respectively), with stronger association with exposure to multiple herpes viruses (β = -0.25, p = 7.28 × 10-10). There were no significant interactions between exposure and group status.

CONCLUSIONS

Latent/persistent herpes virus infections can be associated with cognitive impairments regardless of other health status.

Heritability of functioning in families with schizophrenia in relation to neurocognition

The role of daily functioning is an integral part of the schizophrenia (SZ) phenotype and deficits in this trait appear to be present in both affected persons and some unaffected relatives; hence we have examined its heritability in our cohort of African American schizophrenia families. There is now ample evidence that deficits in cognitive function can impact family members who are not themselves diagnosed with SZ; there is some, but less evidence that role function behaves likewise. We evaluate whether role function tends to "run in families" who were ascertained because they contain an African American proband diagnosed with SZ.

METHODS

We analyzed heritability for selected traits related to daily function, employment, living situation, marital status, and Global Assessment Scale (GAS) score; modeling age, gender, along with neurocognition and diagnosis as covariates in a family based African-American sample (N=2488 individuals including 979 probands).

RESULTS

Measures of role function were heritable in models including neurocognitive domains and factor analytically derived neurocognitive summary scores and demographics as covariates; the most heritable estimate was obtained from the current GAS scores (h2=0.72). Neurocognition was not a significant contributor to heritability of role function.

CONCLUSIONS

Commonly assessed demographic and clinical indicators of functioning are heritable with a global rating of functioning being the most heritable. Measures of neurocognition had little impact on heritability of functioning overall. The family covariance for functioning, reflected in its heritability, supports the concept that interventions at the family level, such as evidenced-based family psychoeducation may be beneficial in schizophrenia.

A polymorphism in SOD2 is associated with development of Alzheimer's disease

Genes involved in cellular mechanisms to repair oxidative damage are strong candidates as etiologic factors for Alzheimer's disease (AD). One important enzyme involved in this mechanism is superoxide dismutase 2 (SOD2). The gene for this enzyme lies within a single haplotype block at 6q25.3, a region showing evidence for linkage to AD in a genome scan. We genotyped four single nucleotide polymorphisms (SNPs) in SOD2 in families of the National Institute of Mental Health-AD Genetics Initiative (ADGI): rs2758346 in the 5' untranslated region (UTR), rs4880 in exon 2, rs2855116 in intron 3 and rs5746136 in the 3'UTR. Under a dominant model, family-based association tests showed significant evidence for association of AD with the first three loci in a candidate gene set of families with individuals having age of onset of at least 50 years and two affected and one unaffected sibling, and in a late-onset subset of families (families with all affected individuals having age of onset of at least 65 years) from the full ADGI sample. The alleles transmitted more frequently to cases than expected under the null hypothesis were T, C, G, and G. Global tests of the transmission of haplotypes indicate that the first two loci have the most consistent association with risk of AD. Because of the high linkage disequilibrium in this small (14 kb) gene, and the presence of 100 SNPs in this gene, 26 of which may have functional significance, additional genotyping and sequencing are needed to identify the functionally relevant SNP. We discuss the importance of our findings and the relevance of SOD2 to AD risk.

Mode of delivery and other maternal factors influence the acquisition of Streptococcus mutans in infants

S. mutans plays a key role in dental caries. The extent to which perinatal events influence the acquisition of S. mutans is unclear. We hypothesized that several maternal factors, including the mode of delivery, influence the initial acquisition of S. mutans in infants. A prospective cohort study was conducted in 156 mother-infant pairs. The study found that maternal gestational age (p = 0.04), S. mutans level (p = 0.02), caries score (p = 0.02), sexually transmitted disease (STD) infection experience (p = 0.01), and family income (p = 0.03) had significant effects on the acquisition of S. mutans. Among infants who became infected, those delivered by Caesarean section acquired S. mutans 11.7 mos earlier than did vaginally delivered infants (p = 0.038). C-section infants harbored a single genotype of S. mutans that was identical to that of their mothers (100% fidelity). Analysis of the data demonstrated the possible perinatal influences on infants' acquisition of a member of the cariogenic microbiota, and its potential effect on caries outcome.

Lack of effect of chlorhexidine varnish on Streptococcus mutans transmission and caries in mothers and children

In a randomized clinical trial, we evaluated the effect of a 10% chlorhexidine varnish (Chlorzoin) on the mother-child transmission of Streptococcus mutans and on subsequent caries experience. Chlorhexidine (n = 38) or a placebo varnish (n = 37) was applied to the dentitions of 75 mothers at a time when their first babies were about 6 months old (approximate time of first tooth emergence). Three more applications at weekly intervals and subsequent applications at 6-month intervals followed the initial application. The mother-child pairs were followed up until the child's fourth birthday. Maternal salivary S. mutans levels in the treatment group remained significantly lower (p < 0.05) compared to the control group up to 12 months after the initial application. However, this intervention did not significantly alter the S. mutans colonization in children or the caries increment in either the mother or the child.

Ectopically expressed CAG repeats cause intranuclear inclusions and a progressive late onset neurological phenotype in the mouse

The mutations responsible for several human neurodegenerative disorders are expansions of translated CAG repeats beyond a normal size range. To address the role of repeat context, we have introduced a 146-unit CAG repeat into the mouse hypoxanthine phosphoribosyltransferase gene (Hprt). Mutant mice express a form of the HPRT protein that contains a long polyglutamine repeat. These mice develop a phenotype similar to the human translated CAG repeat disorders. Repeat containing mice show a late onset neurological phenotype that progresses to premature death. Neuronal intranuclear inclusions are present in affected mice. Our results show that CAG repeats do not need to be located within one of the classic repeat disorder genes to have a neurotoxic effect.