Social class across the life course and physical activity at age 34 years in the 1970 British birth cohort

PurposeTo examine the associations between social class at ages 0, 5, 10, 30, and 34 years and physical activity at age 34 years using a novel approach to analysis of life course data.MethodsWe used structural equation modeling to compare three competing models in life course epidemiology: the accumulation of risk model with additive effects, the accumulation of risk model with trigger effect, and the critical period model. Data were from a nationally representative prospective cohort of 16,571 British men and women born in 1970. Outcomes were physical activity during leisure time, during transports, and at work.ResultsFor all three domains of physical activity, for men and women, the accumulation of risk model with additive effects fit the data best. In this model, social class at ages 0, 5, 10, 30, and 34 years were associated with physical activity at age 34 years, although the magnitude and the direction of the associations for social class at each age varied by physical activity outcome and by sex.ConclusionsStructural equation modeling appears to be a helpful tool in selecting among competing models in life course epidemiology.     

Suicide among people with epilepsy: A population-based analysis of data from the U.S. National Violent Death Reporting System, 17 states, 2003–2011

ObjectiveThis study analyzed suicide data in the general population from the U.S. National Violent Death Reporting System (NVDRS) to investigate suicide burden among those with epilepsy and risk factors associated with suicide and to suggest measures to prevent suicide among people with epilepsy.MethodsThe NVDRS is a multiple-state, population-based, active surveillance system that collects information on violent deaths including suicide. Among people 10 years old and older, we identified 972 suicide cases with epilepsy and 81,529 suicide cases without epilepsy in 17 states from 2003 through 2011. We estimated their suicide rates, evaluated suicide risk among people with epilepsy, and investigated suicide risk factors specific to epilepsy by comparing those with and without epilepsy. In 16 of the 17 states providing continual data from 2005 through 2011, we also compared suicide trends in people with epilepsy (n = 833) and without epilepsy (n = 68,662).ResultsFrom 2003 through 2011, the estimated annual suicide mortality rate among people with epilepsy was 16.89/100,000 per persons, 22% higher than that in the general population. Compared with those without epilepsy, those with epilepsy were more likely to have died from suicide in houses, apartments, or residential institutions (81% vs. 76%, respectively) and were twice as likely to poison themselves (38% vs. 17%) (P < 0.01). More of those with epilepsy aged 40–49 died from suicide than comparably aged persons without epilepsy (29% vs. 22%) (P < 0.01). The proportion of suicides among those with epilepsy increased steadily from 2005 through 2010, peaking significantly in 2010 before falling.SignificanceFor the first time, the suicide rate among people with epilepsy in a large U.S. general population was estimated, and the suicide risk exceeded that in the general population. Suicide prevention efforts should target people with epilepsy 40–49 years old. Additional preventive efforts include reducing the availability or exposure to poisons, especially at home, and supporting other evidence-based programs to reduce mental illness comorbidity associated with suicide.     

Hepatitis B and hepatitis C viral infections in patients with chronic lymphocytic leukemia

BACKGROUND:

Whether chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections contribute to the pathogenesis and/or course of chronic lymphocytic leukemia is unclear.

OBJECTIVE:

To document the prevalences of HBV and HCV infections in chronic lymphocytic leukemia patients, and to determine whether infected patients experience more aggressive disease than those without infection.

METHODS:

Patient sera were screened for antibodies to HBV core antigen and HCV (anti-HCV) using ELISA; both sera and peripheral blood lymphocytes were further tested (regardless of antibody results) for HBV-DNA and HCV-RNA using real-time polymerase chain reaction. Prognostic markers for chronic lymphocytic leukemia included Rai stage, IgV_H mutational status, β₂-microglobulin levels, Zap-70 and CD38 status.

RESULTS:

Fourteen of 222 (6.3%) chronic lymphocytic leukemia patients and two of 72 (2.8%) healthy controls tested positive for previous or ongoing HBV infection (OR 2.4 [95% CI 0.5 to 7.7]; P=0.25) while four of 222 (1.8%) chronic lymphocytic leukemia patients and one of 72 (1.4%) controls tested positive for HCV markers (OR 1.3 [95% CI 0.2 to 6.4]; P=0.81). The levels and distribution of the various indicators of aggressive chronic lymphocytic leukemia disease were similar among HBV- and HCV-infected and uninfected patients. Survival times were also similar. Occult HBV and HCV infection (HBV-DNA or HCV-RNA positive in the absence of diagnostic serological markers) were uncommon in chronic lymphocytic leukemia patients (0.5% and 1.8%, respectively).

CONCLUSIONS:

The results of the present study do not support the hypothesis that HBV or HCV infections play an important role in the pathogenesis or course of chronic lymphocytic leukemia.     

Clinical and electrophysiological features of acute flaccid myelitis: A national cohort study

ObjectiveTo summarize the neurophysiological properties of acute flaccid myelitis (AFM) and evaluate limb-based motor outcomes.MethodsNerve conduction studies (NCS) in 49 patients (21 females, 28 males; median age = 52 m) with AFM (median = 7 d after onset; range 1–122 d) were reviewed. Neurophysiological findings, together with treatment and prognosis, and neurophysiology–neuroimaging correlations were analyzed.ResultsThe findings indicated that 64% of paralytic limbs during the acute stage (≤14 d after onset) showed diminished or absent compound muscle action potentials (CMAPs), 79% showed normal motor nerve conduction velocities, 55% showed decreased persistence or absent F-waves, and 95% showed normal sensory nerve conduction velocities. The rate of CMAP abnormalities increased from 41% on days 1–2 to 83% on days 13–14. The reduction in CMAP amplitude was correlated with weaker muscle strength at both the peak neurological deficit and the last follow-up. The baseline limb-based muscle strength at nadir and anterior horn-localized magnetic resonance imaging lesions at recovery stage (>14 d) were strong predictors of outcome at the last follow-up.ConclusionsAFM typically shows neurophysiological features of neuronopathy.SignificanceNCS is probably useful in the diagnosis and evaluation of AFM.