Alkistis Skalkidou

A role of sunshine in the triggering of suicide

Several reports indicate that suicide follows a seasonal pattern with a dominant peak during the month of maximum daylight. The purpose of this study was to evaluate the hypothesis that sunshine exposure may trigger suicidal behavior. We found a remarkably consistent pattern of seasonality with peak incidence around June in the northern hemisphere and December in the southern hemisphere. Moreover, there was a positive association between the seasonal amplitude of suicide (measured by relative risk) and total sunshine in the corresponding country. These findings indicate that sunshine may have a triggering effect on suicide, and suggests further research in the field of sunshine-regulated hormones, particularly melatonin.

Low adiponectin levels are associated with renal cell carcinoma: a case-control study.

Adiponectin is a novel endogenous insulin sensitizer, secreted by mature adipocytes. Circulating levels of adiponectin are inversely associated with obesity and insulin resistance. Because obesity is a risk factor for renal cell carcinoma (RCC), we hypothesized that low adiponectin levels are associated with RCC. To evaluate this hypothesis, we conducted a case‐ control study of 70 patients with histologically confirmed RCC and 280 healthy controls matched by gender, age and county of residence. Study subjects were interviewed and blood samples were collected during a 32‐month period in Athens, Greece. Serum adiponectin levels were statistically, significantly and inversely associated with RCC when compared with controls (OR = 0.76, p = 0.05) and this association remained practically unchanged after controlling for BMI; the introduction of waist to hip ratio along with adiponectin in the multiple logistic regression analysis model rendered the association between adiponectin and RCC risk insignificant, indicating that altered levels of adiponectin may mediate the effect of central or intra‐abdominal obesity on RCC. Prospective studies as well as studies exploring underlying mechanisms are needed to fully explore the role of adiponectin in predicting future risk of RCC in humans.

Factors affecting motorcycle helmet use in the population of Greater Athens, Greece

Objectives—Helmet use is the best preventive measure available against two wheel motorized vehicle (TWMV) related head injuries. In some countries, however, helmets are used only by a minority of TWMV riders. In collaboration with the Road Traffic Police Department, an inspection survey was undertaken to assess the prevalence and to determine predictors of helmet use. Setting—The Greater Athens area, Greece, during July and August 1998. Methods—A total of 982 TWMVs were stopped, 349 of which had two riders (36%). All riders were interviewed by staff members of the Centre for Research and Prevention of Injuries among the Young. Results—The average prevalence of helmet use was 20.2%. It ranged from 9.7% on small suburban roads to 50.8% on highways. Prevalence of use was significantly lower during the weekend days and at night. Women were significantly more likely to wear a helmet and, controlling for gender, drivers were significantly more likely to be helmet users. Riders of more powerful TWMVs and passengers, who themselves had a TWMV driving license, were helmet users more frequently. Among non-users, the majority (46%) indicated that “the helmet made them feel uncomfortable”, particularly in warm weather, whereas 18% claimed that there was little need for a helmet in low speed riding. Conclusions—A multipronged campaign is urgently needed in Greece to increase the prevalence of helmet use by TWMV riders. The campaign should include not only police enforcement but also initiatives to make helmets more convenient to wear and less expensive.

Controlled ovarian hyperstimulation for IVF: impact on ovarian, endometrial and cervical cancer—a systematic review and meta-analysis

BACKGROUND In response to the ongoing debate on the long-term effects of assisted reproduction technologies, such as IVF, we systematically reviewed and meta-analyzed available evidence on the association between controlled ovarian hyperstimulation for IVF and risk of ovarian, endometrial and cervical cancer. METHODS Eligible studies were identified and pooled effect estimates for relative risk (RR) were calculated by cancer type among two reference groups (general population or infertile women), through fixed- or random-effects models as appropriate. RESULTS Nine cohort studies were synthesized, corresponding to a total size of 109 969 women exposed to IVF, among whom 76 incident cases of ovarian, 18 of endometrial and 207 cases of cervical cancer were studied. The synthesis of studies with general population as the reference group pointed to a statistically significant positive association between IVF and increased risk for ovarian (RR = 1.50, 95% confidence interval (CI): 1.17-1.92) and endometrial (RR = 2.04, 95% CI: 1.22-3.43), but not cervical (RR = 0.86, 95% CI: 0.49-1.49) cancers. On the contrary, when infertile women were used as the reference group, no significant associations with ovarian, endometrial or cervical cancer types were noted (RR = 1.26, 95% CI: 0.62-2.55 RR = 0.45, 95% CI: 0.18-1.14 and RR = 5.70, 95% CI: 0.28-117.20, respectively). CONCLUSIONS IVF does not seem to be associated with elevated cervical cancer risk, nor with ovarian or endometrial cancer when the confounding effect of infertility was neutralized in studies allowing such comparisons. Of note, only one study provided follow-up longer than 10 years for the group exposed to IVF. Future cohort studies should preferably use infertile women as the reference group, rely on IVF-registered valid exposure data, adjust for a variety of meaningful confounders and adopt relatively longer follow-up periods before sound conclusions are drawn.

The effects of maternal depression and maternal selective serotonin reuptake inhibitor exposure on offspring

It has been estimated that 20% of pregnant women suffer from depression and it is well-documented that maternal depression can have long-lasting effects on the child. Currently, common treatment for maternal depression has been the selective serotonin reuptake inhibitor medications (SSRIs) which are used by 2–3% of pregnant women in the Nordic countries and by up to 10% of pregnant women in the United States. Antidepressants cross the placenta and are transferred to the fetus, thus, the question arises as to whether children of women taking antidepressants are at risk for altered neurodevelopmental outcomes and, if so, whether the risks are due to SSRI medication exposure or to the underlying maternal depression. This review considers the effects of maternal depression and SSRI exposure on offspring development in both clinical and preclinical populations. As it is impossible in humans to study the effects of SSRIs without taking into account the possible underlying effects of maternal depression (healthy pregnant women do not take SSRIs), animal models are of great value. For example, rodents can be used to determine the effects of maternal depression and/or perinatal SSRI exposure on offspring outcomes. Unraveling the joint (or separate) effects of maternal depression and SSRI exposure will provide more insights into the risks or benefits of SSRI exposure during gestation and will help women make informed decisions about using SSRIs during pregnancy.

Circulating adiponectin levels and expression of adiponectin receptors in relation to lung cancer : two case-control studies

Background: Decreased circulating levels of adiponectin, an adipocyte-secreted hormone and endogenous insulin sensitizer, have been associated with several obesity-related malignancies. Thiazolidinedione administration, which increases adiponectin levels, decreases risk for lung cancer. Whether circulating adiponectin levels are associated with lung cancer and/or whether adiponectin receptors are expressed in lung cancer remains unknown. Methods: We conducted a case-control study of 85 patients with incidental, histologically confirmed lung cancer and 170 healthy controls matched by gender and age. In a separate study, archival lung specimens from 134 cancerous and 8 noncancerous tissues were examined for relative expression of adiponectin receptors AdipoR1 and AdipoR2 using immunohistochemistry. Results: Tobacco smoking, heavy alcohol intake and education were all associated with lung cancer risk, whereas serum adiponectin levels were not significantly different between cases and controls (multiple logistic regression, odds ratio per SD of adiponectin among controls: 1.13, 95% confidence interval: 0.64–2.02). Adiponectin levels were significantly lower (odds ratio: 0.25, 95% confidence interval: 0.10–0.78) among patients with advanced compared to those with limited disease stage. Expression of adiponectin receptors was apparent only in the cancerous lung tissue (64.2% AdipoR1 and 61.9% AdipoR2 in cancerous vs. 0% among noncancerous tissue). Specifically, AdipoR1 was expressed in all disease types, but no difference was noted with disease stage, whereas AdipoR2 was mainly expressed in the non-small cell carcinomas and more prominently in the advanced disease stage (80%). Conclusions: Circulating adiponectin levels are not different in cases of this malignancy – which seems to be unrelated to obesity and insulin resistance – compared to their healthy controls, though hormonal levels were significantly lower in advanced versus limited lung cancer. Both adiponectin receptors were expressed in cancerous lung tissue, but not in normal control tissue and there was a differential expression by disease stage. These findings should be further explored, especially in the context of the recently reported protective effect of thiazolidinediones in diabetic patients with lung cancer.

Insulin-like growth factor-I and binding protein-3 in relation to childhood leukaemia

The aetiology of most cases of childhood leukaemia remains unknown, but several studies have indicated that increased birthweight and height are risk factors for the disease. Since insulin‐like growth factor‐I (IGF‐I) mediates the effect of growth hormone and has been positively associated with prostate cancer, we have evaluated the role of this hormone and its principal binding protein, IGFBP‐3, in the aetiology of childhood leukaemia. Incident cases of childhood leukaemia from those recorded by a national network of childhood oncologists were enrolled in our study. Controls were children hospitalised for acute conditions of no more than moderate severity with matching for gender, age and maternal place of residence. Blood measurements of IGF‐I and IGFBP‐3 were undertaken using commercially available radioimmunoassays. Serum IGF‐I values decreased by about 1.7% per month, and the rate of decline was higher, though not significantly so, among cases (2.1% per month) than among controls (1.4%). There was no significant association between IGF‐I and the likelihood of childhood leukaemia, but an increment of 1 μg/ml of IGFBP‐3 was associated with a substantial and statistically significant reduction of childhood leukaemia by 28% (95% confidence interval 7% to 45%). Because IGFBP‐3 is essentially a binding protein, we interpret our findings as indicating that bioavailable IGF‐I may play an important role in the aetiology of childhood leukaemia. The much smaller quantities and the inherent instability of IGF‐I in the blood in comparison to those of IGFBP‐3 are likely to hinder documentation of an underlying positive association of IGF‐I with the disease. Int. J. Cancer80:494–496, 1999.

Neonatal leptin levels are strongly associated with female gender, birth length, IGF-I levels and formula feeding.

Objective  To investigate predictors of circulating leptin in healthy full‐term newborns and to explore the relationship with anthropometric variables, serum levels of adiponectin and the major components of the IGF system at birth. To explore whether leptin levels are regulated by breastfeeding vs. formula feeding.

In vitro fertilization and risk of childhood leukemia in Greece and Sweden.

Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets.

IVF and breast cancer: a systematic review and meta-analysis

BACKGROUND The effects of controlled ovarian hyperstimulation (COH) for IVF in terms of breast cancer risk remain controversial, despite the hormone-dependent nature of the latter. METHODS Eligible studies up to 15 February 2013 were identified and pooled effect estimates for relative risk (RR) were calculated separately for the investigations using the general population and those using infertile women, as a reference group. Fixed- or random-effects models were implemented and subgroup analyses were performed, as appropriate. RESULTS Eight cohort studies were synthesized, yielding a total cohort size of 1,554,332 women among whom 14,961 incident breast cancer cases occurred, encompassing 576 incident breast cancer cases among women exposed to IVF. No significant association between IVF and breast cancer was observed either in the group of studies treating the general population (RR = 0.91, 95% confidence interval (CI): 0.74-1.11) or infertile women (RR = 1.02, 95% CI: 0.88-1.18), as a reference group. Of note were the marginal associations, protective for pregnant and/or parous women after IVF (pooled effect estimate = 0.86, 95% CI: 0.73-1.01) and adverse for women <30 years at first IVF treatment (pooled effect estimate = 1.64, 95% CI: 0.96-2.80). CONCLUSIONS At present, COH for IVF does not seem to impart increased breast cancer risk. Longer follow-up periods, comparisons versus infertile women, subgroup analyses aiming to trace vulnerable subgroups, adjustment for various confounders and larger informative data sets are needed before conclusive statements for the safety of the procedure are reached.