Consumption of Olive Oil and Diet Quality and Risk of Dementia-Related Death.

Importance: Age-standardized dementia mortality rates are on the rise. Whether long-term consumption of olive oil and diet quality are associated with dementia-related death is unknown. Objective: To examine the association of olive oil intake with the subsequent risk of dementia-related death and assess the joint association with diet quality and substitution for other fats. Design, Setting, and Participants: This prospective cohort study examined data from the Nurses' Health Study (NHS; 1990-2018) and Health Professionals Follow-Up Study (HPFS; 1990-2018). The population included women from the NHS and men from the HPFS who were free of cardiovascular disease and cancer at baseline. Data were analyzed from May 2022 to July 2023. Exposures: Olive oil intake was assessed every 4 years using a food frequency questionnaire and categorized as (1) never or less than once per month, (2) greater than 0 to less than or equal to 4.5 g/d, (3) greater than 4.5 g/d to less than or equal to 7 g/d, and (4) greater than 7 g/d. Diet quality was based on the Alternative Healthy Eating Index and Mediterranean Diet score. Main Outcome and Measure: Dementia death was ascertained from death records. Multivariable Cox proportional hazards regressions were used to estimate hazard ratios (HRs) and 95% CIs adjusted for confounders including genetic, sociodemographic, and lifestyle factors. Results: Of 92 383 participants, 60 582 (65.6%) were women and the mean (SD) age was 56.4 (8.0) years. During 28 years of follow-up (2 183 095 person-years), 4751 dementia-related deaths occurred. Individuals who were homozygous for the apolipoprotein ε4 (APOE ε4) allele were 5 to 9 times more likely to die with dementia. Consuming at least 7 g/d of olive oil was associated with a 28% lower risk of dementia-related death (adjusted pooled HR, 0.72 [95% CI, 0.64-0.81]) compared with never or rarely consuming olive oil (P for trend < .001); results were consistent after further adjustment for APOE ε4. No interaction by diet quality scores was found. In modeled substitution analyses, replacing 5 g/d of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8% (95% CI, 4%-12%) to 14% (95% CI, 7%-20%) lower risk of dementia mortality. Substitutions for other vegetable oils or butter were not significant. Conclusions and Relevance: In US adults, higher olive oil intake was associated with a lower risk of dementia-related mortality, irrespective of diet quality. Beyond heart health, the findings extend the current dietary recommendations of choosing olive oil and other vegetable oils for cognitive-related health.

Serologic Response to the Epstein-Barr Virus Peptidome and the Risk for Multiple Sclerosis.

Importance: It remains unclear why only a small proportion of individuals infected with the Epstein-Barr virus (EBV) develop multiple sclerosis (MS) and what the underlying mechanisms are. Objective: To assess the serologic response to all EBV peptides before the first symptoms of MS occur, determine whether the disease is associated with a distinct immune response to EBV, and evaluate whether specific EBV epitopes drive this response. Design, Setting, and Participants: In this prospective, nested case-control study, individuals were selected among US military personnel with serum samples stored in the US Department of Defense Serum Repository. Individuals with MS had serum collected at a median 1 year before onset (reported to the military in 2000-2011) and were matched to controls for age, sex, race and ethnicity, blood collection, and military branch. No individuals were excluded. The data were analyzed between September 1, 2022, and August 31, 2023. Exposure: Antibodies (enrichment z scores) to the human virome measured using VirScan (phage-displayed immunoprecipitation and sequencing). Main Outcome and Measure: Rate ratios (RRs) for MS for antibodies to 2263 EBV peptides (the EBV peptidome) were estimated using conditional logistic regression, adjusting for total anti-EBV nuclear antigen 1 (EBNA-1) antibodies, which have consistently been associated with a higher MS risk. The role of antibodies against other viral peptides was also explored. Results: A total of 30 individuals with MS were matched with 30 controls. Mean (SD) age at sample collection was 27.8 (6.5) years; 46 of 60 participants (76.7%) were male. The antibody response to the EBV peptidome was stronger in individuals with MS, but without a discernible pattern. The antibody responses to 66 EBV peptides, the majority mapping to EBNA antigens, were significantly higher in preonset sera from individuals with MS (RR of highest vs lowest tertile of antibody enrichment, 33.4; 95% CI, 2.5-448.4; P for trend = .008). Higher total anti-EBNA-1 antibodies were also associated with an elevated MS risk (top vs bottom tertile: RR, 27.6; 95% CI, 2.3-327.6; P for trend = .008). After adjusting for total anti-EBNA-1 antibodies, risk estimates from most EBV peptides analyses were attenuated, with 4 remaining significantly associated with MS, the strongest within EBNA-6/EBNA-3C, while the association between total anti-EBNA-1 antibodies and MS persisted. Conclusion and Relevance: These findings suggest that antibody response to EBNA-1 may be the strongest serologic risk factor for MS. No single EBV peptide stood out as being selectively targeted in individuals with MS but not controls. Larger investigations are needed to explore possible heterogeneity of anti-EBV humoral immunity in MS.

Flavonoid intake and risk of Parkinson's disease.

BACKGROUND: Flavonoids have been proposed to reduce the risk of Parkinson's disease (PD). However, results from epidemiological studies have been inconclusive. OBJECTIVE: To prospectively examine the association between the intake of flavonoids and their subclasses and the risk of PD and how pesticides may confound or modify that association. METHODS: The study population comprised 80 701 women (1984-2016) and 48 782 men (1986-2016) from two large US cohorts. Flavonoid intake was ascertained at baseline and every 4 years thereafter using a semiquantitative Food Frequency Questionnaire. We conducted multivariable-adjusted Cox regression models to estimate HRs and 95% CIs of PD according to quintiles of baseline and cumulative average intakes of flavonoids and subclasses. We repeated the analyses, adjusting for intakes of high-pesticide-residue fruits and vegetables (FVs) and stratifying by servings/day of high-pesticide-residue FV intake. RESULTS: We identified 676 incident PD cases in women and 714 in men after 30-32 years of follow-up. Higher total flavonoid intake at baseline was not associated with a lower PD risk, neither in men (HR comparing highest to lowest quintile: 0.89, 95% CI: 0.69 to 1.14) nor in women (HR comparing highest to lowest quintile: 1.27, 95% CI: 0.98 to 1.64). Similar results were observed for cumulative average intakes and flavonoid subclasses. Results remained similar after adjustment for and stratification by high-pesticide-residue FV and when analyses were restricted to younger PD cases. CONCLUSION: These results do not support a protective effect of flavonoid intake on PD risk. Pesticide residues do not confound or modify the association.

Smoking and multiple sclerosis risk in black people: A nested case-control study.

BACKGROUND: Smoking is a well-established risk factor for MS; however, it is not known whether its effect on disease risk varies by race/ethnicity. METHODS: We conducted a nested case-control study among US military personnel who have serum samples stored at the Department of Defense Serum Repository. We measured serum cotinine levels, a marker of tobacco smoke exposure, in 157 Black and 23 White individuals who developed MS during follow-up. Controls were randomly selected and matched to each case by age, sex, race/ethnicity, dates of sample collection, and branch of military service. RESULTS: Smoking was not associated with an increased risk of MS in Black people (RR: 1.08, 95 % CI: 0.63-1.85). The results remained similar in analyses restricted to smoking status at baseline, to samples collected 5 years before symptom onset, and using different cut-off levels in cotinine to define smoking status. Smoking was not statistically significantly associated with MS risk in White people, but the point estimate was similar to what has previously been reported in other studies (RR: 1.85, 95 % CI: 0.56-6.16). CONCLUSIONS: Smoking was not associated with MS risk in Black people. Given the consistent association between smoking and MS risk in predominantly White populations, this may suggest that the association between smoking and MS varies by race/ethnicity.

Association Between Use of Any of the Drugs Prescribed in Norway and the Subsequent Risk of Parkinson Disease: A Drug-wide Association Study.

BACKGROUND AND OBJECTIVES: The incidence rate of Parkinson disease (PD) has been increasing rapidly during the past years. Yet, no treatments exist to prevent or slow the progression of the disease. Moreover, we are unable to detect early disease stages during which intervention with disease-modifying therapies is most likely to succeed. The objective of this study was to perform an agnostic drug-wide association study estimating the association between the use of any of the drugs prescribed in Norway and the subsequent risk of PD. METHODS: This registry-based cohort study use data from the entire Norwegian population between 2004 and 2019 linked to the Norwegian Prescription Registry, with more than 600 million individual prescriptions. Drug classes were screened according to Anatomical Therapeutic Chemical codes at level 2, corresponding to therapeutic subgroups. We used Cox regression models to estimate hazard ratios (HRs) and 95% CIs for the associations between drug classes and PD risk. All p values were corrected for multiple testing using the false discovery rate. In addition, we conducted sensitivity analyses of exposure definition as well as time-lag and dose-response analyses. RESULTS: The study population comprised 3,223,672 individuals, 15,849 of whom developed PD during the follow-up. We identified 31 drug classes that were statistically significantly associated with PD risk in Norway during the follow-up. Drugs acting on the renin-angiotensin system (HR 0.92, 95% CI 0.89-0.95), corticosteroids for systemic use (0.88, 95% CI 0.84-0.93), and vaccines (0.89, 95% CI 0.82-0.96) were associated with a decreased risk of PD even up to 10 years before PD onset. Drug classes used to treat symptoms related to prodromal signs of PD, such as constipation, urological issues, and depression, were associated with an increased risk of subsequent diagnosis of PD with HRs of 1.6 (95% CI 1.49-1.73), 1.48 (1.42-1.53), and 1.94 (1.87-2.01), respectively. DISCUSSION: This drug-wide study identified 31 drug classes that were associated with the PD risk change. It reveals the links of renin-angiotensin system medications, vaccines, and corticosteroids with PD risk and suggests that monitoring drug usage using pharmacoepidemiology may allow identifying individuals with prodromal PD.

Childbirth delivery mode and the risk of multiple sclerosis: a prospective population-based study.

BACKGROUND: Caesarean section (CS) may affect the risk of developing multiple sclerosis (MS) in the offspring, possibly through changes in gut microbiota composition, but findings from previous studies are inconsistent. We investigated whether birth by CS was associated with the risk of adult-onset MS. METHODS: We conducted a prospective population-based cohort study, including all individuals born in Norway between 1967 and 2003, using the Medical Birth Registry of Norway linked with the Norwegian Multiple Sclerosis Registry and Biobank. The follow-up was until 2021. We used multivariable Cox models to estimate HRs for MS risk with 95% CIs. RESULTS: Among 2 046 637 individuals in the cohort, 4954 MS cases were identified. Being born by CS was associated with a modest increase in MS risk (HR=1.18, 95% CI 1.05 to 1.32). In the sibling-matched analysis, we found no association between CS and MS risk. We found an interaction between CS and gestational age (p=0.03): CS was associated with an increased risk of MS in individuals born preterm (HR=1.62, 95% CI 1.18 to 2.24), whereas there was no association in individuals born at term (HR=1.13, 95% CI 0.99 to 1.27). In a subgroup analysis of individuals born in 1988 and onwards, emergency CS was related to an elevated MS risk (HR=1.40, 95% CI 1.07 to 1.83), whereas planned CS was not (HR: 1.10, 95% CI 0.77 to 1.58). CONCLUSIONS: CS was associated with a modestly higher risk of developing MS. However, the stronger associations seen in subgroups who likely experienced a more complicated pregnancy/delivery may point to confounding underlying these associations.

Association of Polyunsaturated Fatty Acids and Clinical Progression in Patients With ALS: Post Hoc Analysis of the EMPOWER Trial.

BACKGROUND AND OBJECTIVES: Polyunsaturated fatty acids (PUFAs) have neuroprotective and anti-inflammatory effects and could be beneficial in amyotrophic lateral sclerosis (ALS). Higher dietary intake and plasma levels of PUFAs, in particular alpha-linolenic acid (ALA), have been associated with a lower risk of ALS in large epidemiologic cohort studies, but data on disease progression in patients with ALS are sparse. We examined whether plasma levels of ALA and other PUFAs contributed to predicting survival time and functional decline in patients with ALS. METHODS: We conducted a study among participants in the EMPOWER clinical trial who had plasma samples collected at the time of randomization that were available for fatty acid analyses. Plasma fatty acids were measured using gas chromatography. We used Cox proportional hazards models and linear regression to evaluate the association of individual fatty acids with risk of death and joint rank test score of functional decline and survival. RESULTS: Fatty acid analyses were conducted in 449 participants. The mean (SD) age of these participants at baseline was 57.5 (10.7) years, and 293 (65.3%) were men; 126 (28.1%) died during follow-up. Higher ALA levels were associated with lower risk of death (age-adjusted and sex-adjusted hazard ratio comparing highest vs lowest quartile 0.50, 95% CI 0.29-0.86, p-trend = 0.041) and higher joint rank test score (difference in score according to 1 SD increase 10.7, 95% CI 0.2-21.1, p = 0.045), consistent with a slower functional decline. The estimates remained similar in analyses adjusted for body mass index, race/ethnicity, symptom duration, site of onset, riluzole use, family history of ALS, predicted upright slow vital capacity, and treatment group. Higher levels of the n-3 fatty acid eicosapentaenoic acid and the n-6 fatty acid linoleic acid were associated with a lower risk of death during follow-up. DISCUSSION: Higher levels of ALA were associated with longer survival and slower functional decline in patients with ALS. These results suggest that ALA may have a favorable effect on disease progression in patients with ALS.

Beta2-adrenoreceptor agonists and long-term risk of Parkinson's disease.

INTRODUCTION: There is limited information on how the association between Parkinson's disease and the use of beta2-adrenoreceptor (ß2AR) agonists varies among groups of short-, long-, and ultra-long-acting ß2AR agonists (SABA, LABA and ultraLABA). METHODS: In this prospective study of the Norwegian population, we estimated the incidence of Parkinson's disease according to exposure to ß2AR agonists as a time-dependent variable by means of Cox regression. We adjusted for educational level, comorbidity and performed a sensitivity analysis excluding individuals with chronic obstructive pulmonary disease (COPD), all factors associated with smoking. Anticholinergics and corticosteroids as drugs with the same indication were analyzed for comparison. RESULTS: In the follow-up period from 2005 to 2019, 15,807 incident Parkinson's cases were identified. After adjustments for sex, education and age as the timescale, SABA (Hazard ratio (HR) = 0.84; 95%CI: 0.79, 0.89; p < 0.001), LABA (HR = 0.85; 95%CI: 0.81, 0.90; p < 0.001) and ultraLABA (HR = 0.6; 95%CI: 0.49, 0.73; p < 0.001) were all associated with a lower risk of Parkinson's disease. After exclusion of COPD patients, corticosteroids and anticholinergics were no longer inversely associated, whereas ß2AR agonists remained associated. CONCLUSION: Of drugs with the same indication of use, only ß2AR agonists remained inversely associated with PD risk after all adjustments, with ultraLABA displaying the overall strongest association. Although the precision of the estimate is limited by the modest number of exposed PD cases without COPD, the association is intriguing and suggest that longer-acting, more lipophilic, and thus likely more brain-penetrant ß2AR agonists could be prioritized for further studies.

Abuse and revictimization in adulthood in multiple sclerosis: a cross-sectional study during pregnancy.

BACKGROUND: Knowledge concerning exposure to abuse in adulthood and in pregnancy in people with multiple sclerosis (MS) is sparse. OBJECTIVE: To determine the occurrence of adult abuse and abuse in relation to pregnancy in women with MS and their risk of revictimization (repeated abuse as adults after childhood abuse). METHODS: This cross-sectional study comprised pregnant women from the Norwegian Mother, Father and Child Cohort study. Information on abuse was acquired through self-completed questionnaires. We used logistic regression to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs). RESULTS: We identified 106 women with MS at enrollment through linkage with national health registries. The reference group consisted of 77,278 women without MS. Twenty-seven women (26%) with MS reported any adult abuse compared to 15,491 women (20%) without MS, aOR 1.33 (0.85-2.09). Twenty-two (21%) women with MS reported systematic emotional abuse compared to 13% without MS, aOR 1.75 (1.08-2.83). Ten women (10%) with MS reported sexual abuse, compared to 6% without MS, aOR 1.72 (0.89-3.33). More women with MS reported rape as an adult, aOR 2.37 (1.02-5.49). Women with MS had higher risk of revictimization as adults, after childhood abuse, aOR 2.23 (1.22-4.10). The risk of abuse during pregnancy or 6 months preceding pregnancy was similar between the groups. CONCLUSIONS: Women with MS had increased occurrence of systematic emotional abuse, rape, and revictimization as adults, compared to women without MS.

Association of adverse childhood experiences with the development of multiple sclerosis.

OBJECTIVE: To study whether exposure to childhood emotional, sexual or physical abuse is associated with subsequent multiple sclerosis (MS) development. METHODS: A nationwide, prospective cohort study based on participants in the Norwegian Mother, Father and Child cohort study. Enrolment took place 1999-2008, with follow-up until 31 December 2018. Childhood abuse before age 18 years was obtained from self-completed questionnaires. We identified MS diagnoses through data-linkage with national health registries and hospital records. The Cox model was used to estimate HRs for MS with 95% CIs, adjusting for confounders and mediators. RESULTS: In this prospective cohort study, 14 477 women were exposed to childhood abuse and 63 520 were unexposed. 300 women developed MS during the follow-up period. 71 of these (24%) reported a history of childhood abuse, compared with 14 406 of 77 697 (19%) women that did not develop MS. Sexual abuse (HR 1.65, 95% CI 1.13 to 2.39) and emotional abuse (HR 1.40, 95% CI 1.03 to 1.90) in childhood were both associated with an increased risk of developing MS. The HR of MS after exposure to physical abuse was 1.31 (95% CI 0.83 to 2.06). The risk of MS was further increased if exposed to two (HR 1.66, 95% CI 1.04 to 2.67) or all three abuse categories (HR 1.93, 95% CI 1.02 to 3.67). INTERPRETATION: Childhood sexual and emotional abuse were associated with an increased risk of developing MS. The risk was higher when exposed to several abuse categories, indicating a dose-response relationship. Further studies are needed to identify underlying mechanisms.

Longitudinal analysis reveals high prevalence of Epstein-Barr virus associated with multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system of unknown etiology. We tested the hypothesis that MS is caused by Epstein-Barr virus (EBV) in a cohort comprising more than 10 million young adults on active duty in the US military, 955 of whom were diagnosed with MS during their period of service. Risk of MS increased 32-fold after infection with EBV but was not increased after infection with other viruses, including the similarly transmitted cytomegalovirus. Serum levels of neurofilament light chain, a biomarker of neuroaxonal degeneration, increased only after EBV seroconversion. These findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS.

Body mass index as a predictor of MS activity and progression among participants in BENEFIT.

BACKGROUND: There is a lack of studies on the association between obesity and conversion from a clinically isolated syndrome (CIS) to multiple sclerosis (MS). OBJECTIVE: The aim of this study was to determine whether obesity predicts disease activity and prognosis in patients with CIS. METHODS: Body mass index (BMI) at baseline was available for 464 patients with CIS in BENEFIT. Obesity was defined as BMI ⩾ 30 kg/m2 and normal weight as 18.5 ⩽ BMI < 25. Patients were followed up for 5 years clinically and by magnetic resonance imaging. Hazard of conversion to clinically definite (CDMS) or to 2001 McDonald criteria (MDMS) MS, annual rate of relapse, sustained progression on Expanded Disability Status Scale (EDSS), change in brain and lesion volume, and development of new brain lesions were evaluated. RESULTS: Obese individuals were 39% more likely to convert to MDMS (95% CI: 1.02-1.91, p = 0.04) and had a 59% (95% CI: 1.01-2.31, p = 0.03) higher rate of relapse than individuals with normal weight. No associations were observed between obesity and conversion to CDMS, sustained progression on EDSS or magnetic resonance imaging (MRI) outcomes, except for a larger reduction of brain volume in obese smokers as compared to normal weight smokers (-0.82%; 95% CI: -1.51 to -0.12, p = 0.02). CONCLUSION: Obesity was associated with faster conversion to MS (MDMS) and a higher relapse rate.

Aging with multiple sclerosis: A longitudinal study of physical function, mental health, and memory in two cohorts of US women.

BACKGROUND: It is unknown how individuals with multiple sclerosis (MS) age compared to unaffected peers. OBJECTIVES: The objective of the study is to describe the impact of MS on health and functioning in aging women. METHODS: We used 10-item Physical Functioning Scale (PF10) scores (from the Short Form-36 (SF-36)) and other indicators of general, physical, mental health, and memory collected repeatedly over 25 years with self-administered questionnaires among participants in the Nurses' Health Study (n = 121,700 recruited at ages 30-55) and Nurses' Health Study II (n = 116,429 recruited at ages 25-42) to compare women with MS (n = 733) to unaffected peers in their health and disability, and describe/quantify the burden of aging with MS. RESULTS: Women with MS had a consistently lower PF10 by 0.9-1.7 standard deviations with greater overall variability than unaffected women. PF10-scores gradually decreased with increasing age in both groups, but MS cases declined 3-4 times faster in midlife, while decline was similar in old age. The physical function score of 45-year-old women with MS was comparable to that of 75-year-old unaffected women; 70-year-old women with MS scored similarly to 85-year-old unaffected women. MS cases also reported worse health/more disability throughout adulthood on the other indicators. CONCLUSION: The age-related decline in physical health is accelerated by 15-30 years in MS patients compared to unaffected peers.

The limits of small-for-gestational-age as a high-risk category.

SGA (small for gestational age) is widely used to identify high-risk infants, although with inconsistent definitions. Cut points range from 2.5th to 10th percentile of birthweight-for-gestational age. We used receiver operator characteristic curves (ROC) to identify the cut point with maximum sensitivity and specificity (Youden Index), and the area under the curve (AUC), which assesses overall discriminating power. Analysis was conducted on 3,836,034 US births (2015) and 292,279 Norwegian births (2010-14). Birthweight percentiles were calculated using exact birthweights at each week of gestational age, and then summarized across gestational ages. We also conducted a companion analysis of gestational age itself to consider the predictive power of gestational week of birth. Outcomes were neonatal mortality and cerebral palsy, both strongly associated with birthweight. Birthweight percentiles performed poorly in all analyses. The AUC for birthweight percentiles as a discriminator of neonatal mortality was 60% (where 50% is no better than a coin-toss). At such low discrimination, the Youden Index provides no useful SGA cut point. Results in Norway were virtually identical, with an AUC of 58%. The AUC with cerebral palsy as the outcome was even lower, at 54%. In contrast, gestational age had an AUC of 85% as a predictor of neonatal mortality, with < 37 weeks as the optimum cut point. SGA provides surprisingly poor identification of at-risk infants, while gestational age performs well. Similar results in two countries that differ in mean birthweight, percent preterm, and neonatal mortality suggest robustness across populations.

Maternal prepregnancy BMI and physical activity and type 1 diabetes in the offspring.

BACKGROUND: Previous studies showed conflicting results on the association between maternal prepregnancy body mass index (BMI) and type 1 diabetes in the offspring, and the role of maternal prepregnancy physical activity is unclear. We aimed to assess whether maternal prepregnancy BMI and physical activity predict type 1 diabetes in their offspring. METHODS: Prospective study including women participating in the Nurses' Health Study II with follow-up from 1989 to 2011. Women repeatedly reported their BMI and physical activity, from which prepregnancy exposures were derived; and retrospectively reported their BMI at age 18 and physical activity at ages 18-22, considered early adulthood exposure. We estimated risk ratios (RR) and 95% confidence intervals (95%CI) using generalized estimating equations, adjusted for covariates. Findings at p < 0.05 were considered statistically significant. RESULTS: We identified 276 cases of type 1 diabetes among offspring (n = 70,168) with maternal prepregnancy information and 448 cases among offspring (n = 111,692) with maternal early adulthood information. Prepregnancy and early adulthood maternal BMI and physical activity were not associated with offspring type 1 diabetes. The RR comparing overweight to normal weight mothers was 1.08 (95%CI: 0.73-1.59) and comparing obese to normal weight was 0.94 (95%CI: 0.49-1.79, p-trend: 0.98). Comparing highest to lowest quartile of maternal physical activity the RR was 0.90 (95%CI: 0.61-1.32; p-trend: 0.73). Maternal type 2 diabetes was associated with an increased risk of type 1 diabetes in the offspring (RR = 1.87; 95%CI: 1.25-2.80). CONCLUSIONS: Our findings do not support a relationship between maternal prepregnancy BMI or physical activity and the risk of type 1 diabetes in the offspring.

Exposure to breastfeeding and risk of developing multiple sclerosis.

BACKGROUND: Early-life factors are reported to modulate the risk of developing multiple sclerosis (MS) among adults. The association between exposure to breastfeeding and the risk of MS is debated. We aimed to disclose whether past exposure to breastfeeding and its duration are associated with the risk of developing MS. METHODS: We used a cohort design linking prospectively collected information on breastfeeding from the Cohort of Norway community-based surveys on health status (CONOR) with the Norwegian MS Registry and the population-based Medical Birth Registry of Norway that includes information on all births in Norway since 1967. MS clinical onset was collected throughout 2016. A total of 95 891 offspring born between 1922 and 1986 to mothers participating in CONOR were included. We identified 215 offspring within this cohort who developed adult-onset MS. Associations between breastfeeding and MS risk were estimated as hazard ratios using Cox proportional hazard models adjusting for maternal factors including education. RESULTS: We found no association between having been breastfed for ≥4 months and MS risk, also after adjusting for various maternal factors (hazard ratio = 0.90; 95% confidence interval 0.68-1.19). The estimates did not change for different durations of breastfeeding. The results were similar when adjusting for other perinatal factors. CONCLUSION: Our study could not confirm previous findings of an association between breastfeeding and risk of MS. Breastfeeding information was less likely to be biased by knowledge of disease compared with case-control studies.

Term Birth Weight and Neurodevelopmental Outcomes.

BACKGROUND: Preterm birth is an important risk factor for neurodevelopmental disabilities. The vast majority of these disabilities occur, however, among term births. The role of fetal growth restriction specifically among term babies has been incompletely described. METHODS: We conducted a population-based study of term birth weight and its link to a range of neurodevelopmental outcomes using Norwegian health registries. To remove the influence of preterm birth, we restricted our analyses to 1.8 million singleton babies born during a narrow range of term gestational age (39-41 weeks). Babies with malformations were excluded. We adjusted analyses simply for year of birth, as further adjustments for sex, parity, maternal age, smoking, marital status, immigrant status, and parental education had trivial influence. An additional sibling analysis controlled for unmeasured family-based confounding. RESULTS: The risk of neurodevelopmental disabilities at term steadily increased at birth weights lower than 3.5 kg. Using the category of 3.5-3.9 kg as the reference, the odds reached 25-fold for cerebral palsy at the smallest weights (95% confidence interval 8.0, 79), 16-fold for vision/hearing disability (4.0, 65), 11-fold for intellectual impairment (6.9, 17), 7-fold for schizophrenia (1.0, 50), 5.4-fold for epilepsy (2.6, 12), and 3.5-fold for autism spectrum (1.3, 9.4) and behavioral disorders including attention-deficit hyperactivity disorder (2.1, 5.4). Associations remained robust with sibling controls. CONCLUSIONS: Reduced fetal growth is a powerful predictor of a wide variety of neurodevelopmental disabilities independent of preterm delivery.

Pre-diagnostic plasma lipid levels and the risk of amyotrophic lateral sclerosis.

OBJECTIVE: To assess whether pre-diagnostic lipid levels are associated with Amyotrophic lateral sclerosis (ALS) risk. Methods: We conducted a matched case-control study nested in five large prospective US cohorts (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the Women's Health Initiative), and identified 275 individuals who developed ALS during follow-up and had provided blood samples before disease diagnosis. For each ALS case, we randomly selected two controls who were alive at the time of the case diagnosis and matched on cohort, birth year (±1 year), sex, race/ethnicity, fasting status, and time of blood draw. We measured total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels in the plasma samples, and used conditional logistic regression to estimate associations between lipid levels and ALS risk. Results: Higher levels of HDL-C were associated with higher ALS risk in an analysis adjusted for the matching factors (risk ratio [RR] Q4 vs. Q1: 1.78, 95% confidence interval [CI]: 1.18-2.69, p trend: 0.007). The estimate remained similar in a multivariable analysis additionally adjusted for body mass index, physical activity, smoking, alcohol intake, plasma urate levels, and use of cholesterol-lowering drugs (RR Q4 vs. Q1: 1.71, 95% CI: 1.07-2.73, p trend: 0.02). Plasma levels of TC, LDL-C, and TG were not associated with ALS risk. Conclusions: Higher pre-diagnostic HDL-C levels, but not levels of other lipids, were associated with a higher risk of ALS.

The human gut microbiota in people with amyotrophic lateral sclerosis.

OBJECTIVE: To characterize the gut microbiota in people with amyotrophic lateral sclerosis (ALS) relative to controls and to test the hypothesis that butyrate-producing bacteria are less abundant in the gastrointestinal tracts of people with ALS (PALS). Methods: We conducted a case-control study at Massachusetts General Hospital to compare the gut microbiota in people with ALS to that in controls. Metagenomic shotgun sequencing was performed on DNA extracted from stool samples of 66 people with ALS (PALS), 61 healthy controls (HC), and 12 neurodegenerative controls (NDC). Taxonomic metagenomic profiles were analyzed for shifts in the microbial community structure between the comparator groups using per-feature univariate and multivariate association tests. Results: The relative abundance of the dominant butyrate-producing bacteria Eubacterium rectale and Roseburia intestinalis was significantly lower in ALS patients compared to HC. Adjustment for age, sex, and constipation did not materially change the results. The total abundance of 8 dominant species capable of producing butyrate was also significantly lower in ALS compared to HC (p < 0.001). Conclusions: The levels of several butyrate-producing bacteria, which are important for gut integrity and regulation of inflammation, were lower in people with ALS compared to controls. These findings lend support to the inference that the gut microbiota could be a risk factor for ALS. Further investigations are warranted, preferably earlier in the disease with corresponding dietary collection and a longitudinal design.