Breast cancer risk factors and age at diagnosis: an Icelandic cohort study

An increasing number of studies indicates that the strength and even direction of association between breast cancer and established risk factors differ according to the woman's age when she develops the disease. This was studied in the setting of a population based cancer registry using a databank with information on age at menarche, parity, age at first birth, oral contraceptive (OC) use, lactation, height and weight. From a cohort of 80.219 women attending population-based cervical and breast cancer screening in Iceland, 1120 cases were identified, aged 26-90 years at diagnosis and 10,537 controls, individually matched to the cases on birth year and age when attending. Information given at last visit before diagnosis was used in the analysis, applying conditional logistic regression. Odds ratios and statistical strength of relationships varied according to age at diagnosis for age at first birth, number of births, duration of lactation, height and weight. The decreased risk associated with young age at first birth and increasing duration of breast feeding became less pronounced with advancing age at diagnosis. A reduced risk associated with an increasing number of births was not detected in women diagnosed under the age of 40. An increased risk associated with giving first birth after 30 years of age was mainly detected in women who had only given 1 birth and were diagnosed under the age of 40 (OR = 7.06 95% CI = 2.16-23.01). A positive association with height and especially with weight was confined to women diagnosed after the age of 55. The results confirm that age at diagnosis should be taken into account when studying the effects of breast cancer risk factors.     

Costs and efficiency of gatekeeping under varying numbers of general practitioners

We study the relationship between gatekeeping on one hand and costs as well as efficiency on the other hand. We do this with special focus on the relative amount of general practitioners in the system when compared with all practitioners. Data collected between 2002 and 2011 by The Organization for Economic Co‐operation and Development on 34 countries were analyzed. Of those, 18 countries have gatekeeping systems while 16 do not. The association between gatekeeping and health care costs was examined with regression analysis. Efficiency was assessed with data envelopment analysis. Finally, the efficiency assessments were analyzed with regression techniques to examine if gatekeeping and/or the ratio of GPs to all practitioners was associated with efficiency. Point estimates indicate that total costs tend to be lower in systems where GPs act as gatekeepers. However, efficiency is slightly lower where gatekeeping exists. Neither of these results is statistically significant at the 95% confidence level. There is also indication that the efficiency of a gatekeeping system increases with increased amount of GPs. When GPs are over 30% of practitioners, gatekeeping countries have more efficient health care systems than their counterparts. Consistent with other studies, we estimate income elasticity of health care demand to be 1.12, suggesting that those societies consider health care to be a luxury good.     

Bioavailability of aciclovir after oral administration of aciclovir and its prodrug valaciclovir to patients with leukopenia after chemotherapy

The median bioavailabilities of aciclovir after administration of aciclovir and its prodrug valaciclovir were 21.5 and 70.1%, respectively, in 12 patients with malignant hematological diseases with leukopenia after chemotherapy. The interindividual variations of the bioavailability were 48.5 and 21.0% after administration of aciclovir and valaciclovir, respectively. Neither the bioavailability nor the interindividual variation of area under the concentration-time curve of oral aciclovir or valaciclovir differed from that reported in healthy volunteers.     

Milk consumption throughout life and bone mineral content and density in elderly men and women

Summary

Association between bone mineral density and bone mineral content in old age and milk consumption in adolescence, midlife, and old age was assessed. The association was strongest for milk consumption in midlife: those drinking milk daily or more often had higher bone mineral density and content in old age than those drinking milk seldom or never.

Introduction

The role of lifelong milk consumption for bone mineral density (BMD) and bone mineral content (BMC) in old age is not clear. Here we assess the association between hip BMD and BMC in old age and milk consumption in adolescence, midlife, and current old age.

Methods

Participants of the Age, Gene/Environment Susceptibility-Reykjavik Study, aged 66–96 years (N?=?4,797), reported retrospective milk intake during adolescence and midlife as well as in current old age, using a validated food frequency questionnaire. BMC of femoral neck and trochanteric area was measured by volumetric quantitative computed tomography and BMD obtained. Association was assessed using linear regression models. Differences in BMC, bone volume, and BMD in relation to milk intake were portrayed as gender-specific Z-scores.

Results

Men consuming milk?≥?once/day during midlife had 0.21 higher Z-scores for BMD and 0.18 for BMC in femoral neck (95 % confidence interval 0.05–0.39 and 0.01–0.35, respectively) compared with?<?once/week. Results were comparable for trochanter. For women the results were similar, with slightly lower differences according to midlife milk consumption. For current and adolescent milk consumption, differences in Z-scores were smaller and only reached statistical significance in the case of BMD for current consumption in men, while this association was less pronounced for BMC.

Conclusions

Our data suggest that regular milk consumption throughout life, from adolescence to old age, is associated with higher BMC and BMD in old age, with no differences seen in bone volume. The strongest associations are seen for midlife milk consumption in both genders.     

Vitamin D Intake and Status in 12-Month-Old Infants at 63–66° N

The objective was to assess the vitamin D status in healthy 12-month-old infants in relation to quantity and sources of dietary vitamin D, breastfeeding and seasons. Subjects were 76 12-month-old infants. Serum levels of 25-hydroxyvitamin D (25(OH)D) ≥ 50 nmol/L were considered indicative of vitamin D sufficiency and 25(OH)D < 27.5 nmol/L as being indicative of increased risk for rickets. Additionally, 25(OH)D > 125 nmol/L was considered possibly adversely high. Total vitamin D at 9–12 months (eight data collection days) included intake from diet and supplements. The mean ± SD of vitamin D intake was 8.8 ± 5.2 μg/day and serum 25(OH)D 98.1 ± 32.2 nmol/L (range 39.3–165.5). Ninety-two percent of infants were vitamin D sufficient and none at increased risk for rickets. The 26% infants using fortified products and supplements never/irregularly or in small amounts had lower 25(OH)D (76.8 ± 27.1 nmol/L) than the 22% using fortified products (100.0 ± 31.4 nmol/L), 18% using supplements (104.6 ± 37.0 nmol/L) and 33% using both (110.3 ± 26.6 nmol/L). Five of six infants with 25(OH)D < 50 nmol/L had no intake of supplements or fortified products from 0 to 12 months. Supplement use increased the odds of 25(OH)D > 125 nmol/L. Breastfeeding and season did not affect vitamin D status. The majority of infants were vitamin D sufficient. Our findings highlight the need for vitamin D supplements or fortified products all year round, regardless of breastfeeding.     

Identity matching in a patient with Alzheimer's disease

Difficulties with short-term memory are one of the main problems in patients with dementia. Therefore, one purpose of this study was to examine the effects of simultaneous vs delayed presentation of comparison stimuli in a matching-to-sample (MTS) task using computerized training. By using an identity MTS procedure, the participant was trained to select a comparison stimulus identical to a sample stimulus. A 2nd purpose was to study the effect of the number of choices presented, thereby evaluating short-term memory deficits and possible deterioration of deficits over time. In this study, an 80-year-old-male with a Mini-Mental State Examination (MMSE) score of 10 was exposed to 4 experimental conditions. The results showed that using 3 comparison stimuli presented simultaneously with the sample stimulus on the screen resulted in more incorrect responding than when using 2 comparison stimuli. Furthermore, when adding a 0-second delay between the presentation of the sample stimulus and the 2 comparison stimuli, the number of correct responses did not exceed chance level.     

Pelvic floor muscle function before and after first childbirth

Introduction and hypothesis  

Pregnancy and vaginal delivery are considered to be the main risk factors for development of pelvic floor dysfunction. We hypothesize that; 1) pelvic floor muscle (PFM) strength and endurance is significantly reduced by first delivery in general, and 2) changes in PFM strength and endurance are influenced by mode of delivery.     

European genome-wide association study identifies SLC14A1 as a new urinary bladder cancer susceptibility gene

Three genome-wide association studies in Europe and the USA have reported eight urinary bladder cancer (UBC) susceptibility loci. Using extended case and control series and 1000 Genomes imputations of 5 340 737 single-nucleotide polymorphisms (SNPs), we searched for additional loci in the European GWAS. The discovery sample set consisted of 1631 cases and 3822 controls from the Netherlands and 603 cases and 37 781 controls from Iceland. For follow-up, we used 3790 cases and 7507 controls from 13 sample sets of European and Iranian ancestry. Based on the discovery analysis, we followed up signals in the urea transporter (UT) gene SLC14A. The strongest signal at this locus was represented by a SNP in intron 3, rs17674580, that reached genome-wide significance in the overall analysis of the discovery and follow-up groups: odds ratio = 1.17, P = 7.6 × 10(-11). SLC14A1 codes for UTs that define the Kidd blood group and are crucial for the maintenance of a constant urea concentration gradient in the renal medulla and, through this, the kidney's ability to concentrate urine. It is speculated that rs17674580, or other sequence variants in LD with it, indirectly modifies UBC risk by affecting urine production. If confirmed, this would support the 'urogenous contact hypothesis' that urine production and voiding frequency modify the risk of UBC.     

Validity of retrospective diet history: Assessing recall of midlife diet using food frequency questionnaire in later life

Objectives

Limited information exists on the validity of dietary information given by elderly people on their past diet. Here we test the relative validity of a food frequency questionnaire asking older persons about their midlife diet.

Design

Retrospective food intake of 56–72-year-old subjects was estimated using a food frequency questionnaire designed for the AGES-Reykjavik Study (AGES-FFQ), an epidemiological study of older individuals. Results were compared with detailed dietary data gathered from the same individuals 18–19 years previously, i.e., in midlife, as part of a national cohort. Spearman correlation and cross-classifications were used to assess the ability of the AGES-FFQ to rank subjects according to their intake.

Setting

Nationwide, Iceland.

Participants

Subjects, born 1937–1952 (n=174), who participated in the 1990 Icelandic National Dietary Survey.

Measurements

Dietary intake, estimated by the AGES-FFQ (2008–2009), and dietary history obtained from the 1990 Icelandic National Dietary Survey as a reference method.

Results

The strongest correlation between the AGES-FFQ and the reference method was found for cod liver oil, r=0.53, p<0.001 and r=0.56, p<0.001, for men and women, respectively. For men the corresponding correlation coefficient for milk and dairy products was r=0.43, p<0.001. The correlation coefficients were lower but within a reasonably acceptable range (r=0.26–0.40) for meat, fish and potatoes for both genders, as well as fresh fruits and milk/dairy products for women and whole-wheat bread, oatmeal/muesli and blood/liver-sausage for men. No correlation was found between the AGES-FFQ and the dietary history for rye bread and vegetable consumption. Subjects were categorized into five groups according to level of consumption by the two methods. Cross-classification showed that 16–59% were classified into same group and 43–91% into same or adjacent group, 0–14% were grossly misclassified into opposite groups.

Conclusion

The AGES-FFQ on midlife diet was found suitable to rank individuals by their intake of several important food groups.