Polychlorinated biphenyl levels in peripheral blood and non-Hodgkin's lymphoma: a report from three cohorts

The incidence of non-Hodgkin's lymphoma (NHL) unrelated to HIV infection has steadily increased over the past several decades and remains substantially unexplained. Limited evidence suggests that increased concentrations of polychlorinated biphenyls (PCB) measured in blood or fat tissue are associated with increased risk of NHL. Although PCB congeners vary in their biological activity, the relation between individual congeners and NHL risk has not been examined previously using prospectively collected biospecimens. We examined congener-specific associations in three prospective cohorts. Prediagnostic serum or plasma concentrations of selected PCB congeners were measured among NHL cases and controls from these cohorts: Janus (190 cases and 190 controls) in Norway and CLUE I (74 cases and 147 controls) and the Nurses' Health Study (30 cases and 78 controls) in the United States. All blood samples were collected in the 1970s or 1980s. We used logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for the relations between risk of NHL and lipid-corrected plasma or serum concentrations. Several congeners (i.e., 118, 138, and 153) that were present at higher levels and were moderately to highly correlated with each other showed exposure-response trends with risk of NHL in all three cohorts. These associations were observed primarily among subjects diagnosed closer to the date of blood collection in the two cohorts with sufficient cases to permit stratification by time. Among cases diagnosed within the median years of follow-up (16 years in Janus and 12 years in CLUE I), ORs and 95% CIs for increasing fourths of concentration of congener 118 relative to the lowest fourth were as follows: 2.4 (0.9-6.5), 4.9 (1.6-15.3), and 5.3 (1.5-18.8; P(trend) < 0.005) in Janus and 8.1 (1.0-68.9), 6.6 (0.7-59.0), and 13.0 (1.6-106.8; P(trend) < 0.05) in CLUE I. Similar patterns were seen for congeners 138 and 153 and for total PCBs. Limited evidence of exposure-response trends was also observed for several other congeners. The primary 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane metabolite, p,p'-DDE, was not significantly associated with NHL in most analyses but slightly to moderately confounded the PCB associations. The results from these three cohorts suggest that concentrations of certain PCBs in blood are associated with increased risk of NHL.     

Paternal depression in the postnatal period assessed with traditional and male depression scales

Background

The occurrence of postnatal depression in fathers has begun to receive attention in the international research literature. The Edinburgh Postnatal Depression Scale (EPDS) assessment tool has been validated for men. However, identification of such men has been hindered by the use of assessment tools that may not be sensitive to the particular depressive symptoms experienced by men. So far the problem of male depressive symptoms has not been included in research on men's postnatal depressions.

Methods

As part of a fatherhood research programme, the EPDS and the Gotland Male Depression Scale (GMDS) were administered to 607 fathers 6 weeks after the birth of their child.

Results

549 (90.4%) fathers were assessed for the presence of depressive symptoms. The prevalence was 5.0% with EPDS (cut-off ≥10) and 3.4% with GMDS (cut-off ≥13). While 2.1% of the fathers had scores above the cut-off on both scales, 3.1% were assessed using only the EPDS and 1.3% with only the GMDS.

Conclusion

Our findings indicate that better methods for identifying men with postnatal depression need to be developed and should consist of assessment scales that also include male depressive symptoms.