Leigh Anne Newhook

Vitamin D insufficiency common in newborns, children and pregnant women living in Newfoundland and Labrador, Canada

Vitamin D deficiency is associated with poor bone health, colorectal cancer, type 1 diabetes and multiple sclerosis. Two national health-related societies in Canada have made recommendations for vitamin D supplementation, yet little research has been reported on the vitamin D status of Canadians. Lifestyle changes, such as sunscreen use, spending less time outdoors and insufficient intake of vitamin D-containing foods as well as northern latitude, may be affecting human vitamin D status. A cross-sectional analysis of 25-hydroxyvitamin D [25-(OH)D] was conducted in pregnant women, newborns (umbilical cord blood) and children. Samples were analysed by liquid chromatography mass spectrometry. Published ranges for 25-(OH)D were used to determine vitamin D status. The prevalence of 25-(OH)D deficiency for the three groups studied revealed most concentrations in the 25-(OH)D deficiency or insufficiency ranges. There were significant differences in all groups studied between seasons, with the exception of maternal blood and female cord blood samples. 25-(OH)D insufficiency was common in all groups for winter and summer, more so in winter. 25-(OH)D insufficiency was common in the three groups studied. The Newfoundland and Labrador population may be at increased risk for vitamin D insufficiency because of factors such as northern latitude and lifestyle issues. Further research on the vitamin D status of this population is important, considering the potential adverse health-related outcomes and the recommendations on supplementation being made.

Obesity prevalence estimates in a Canadian regional population of preschool children using variant growth references

BackgroundChildhood obesity is a public health problem in Canada. Accurate measurement of a health problem is crucial in defining its burden. The objective of this study is to compare the prevalence estimates of overweight and obesity in preschool children using three growth references.MethodsWeights and heights were measured on 1026 preschool children born in Newfoundland and Labrador (NL), Canada, and body mass index calculated. The prevalence of overweight and obesity was determined and statistical comparisons conducted among the three growth references; the Centres for Disease Control (CDC), the International Obesity Task Force (IOTF) and the World Health Organization (WHO).ResultsCDC and IOTF produced similar estimates of the prevalence of overweight, 19.1% versus 18.2% while the WHO reported a higher prevalence 26.7% (p < .001). The CDC classified twice as many children as obese compared to the IOTF 16.6% versus 8.3% (p < .001) and a third more than the WHO 16.6% versus 11.3% (p < .01). There was variable level of agreement between methods.ConclusionsThe CDC reported a much higher prevalence of obesity compared to the other references. The prevalence of childhood obesity is dependent on the growth reference used.

The geospatial relation between UV solar radiation and type 1 diabetes in Newfoundland

Type 1 diabetes (T1DM) has been previously associated with northern latitude and vitamin D insufficiency. This study investigates the geospatial association between average daily ultraviolet B (UVB) irradiance and T1DM across the province of Newfoundland (NL), Canada. NL has one of the highest documented incidences of T1DM worldwide. A complete list of patients diagnosed (1987–2005) with T1DM in the province of Newfoundland and Labrador (NL) was constructed using multiple sources. All places of habitation at diagnosis were ascertained. Ecological analysis using Bayesian estimation was performed employing both NASA UVB data and latitude. Correlation of T1DM to both UVB irradiation and latitude was measured. A statistically significant correlation of erythemal UVB irradiance was observed (−0.0284: 95% CI −0.0542 to −0.0096). A more significant correlation of T1DM was observed with erythemal UVB irradiance than with latitude. This study suggests that erythemal UVB radiation may be geospatially associated with the incidence of T1DM in NL.

Plasma advanced glycation endproduct, methylglyoxal-derived hydroimidazolone is elevated in young, complication-free patients with Type 1 diabetes

OBJECTIVES Elevated advanced glycation endproducts (AGEs) are implicated in diabetic complications. Methylglyoxal-derived hydroimidazolone (MG-H) is one of the most abundant AGEs in vivo. Our objective was to develop a time-saving, specific method to measure free MG-H in plasma and determine its levels in complication-free young individuals with Type 1 diabetes (T1DM). The relationship of plasma free MG-H to hemoglobin A1C (A1C) and plasma methylglyoxal levels was also determined. DESIGN AND METHODS A solid phase extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed, and free plasma MG-H levels were measured in 40 T1DM patients (DM group), aged 6-21 years, and 11 non-diabetics (ND group), 6-22 years. Methylglyoxal was measured using LC-MS/MS and A1C by a Tosoh G7 high-performance liquid chromatograph. RESULTS Our method showed high recovery, sensitivity and short run-time. Plasma free MG-H (nmol/L) was higher (p<0.001) in the DM group (1318+/-569; mean+/-standard deviation) as compared to the ND group (583+/-419). Within the DM group, plasma free MG-H did not correlate with plasma methylglyoxal or A1C. CONCLUSIONS Our LC-MS/MS method to measure free MG-H in plasma may be useful for future clinical application. The increased levels of free MG-H observed in individuals with TIDM are not merely the result of short term changes in glucose or methylglyoxal, but may reflect long-term alterations to tissue proteins.

To the editor [3]

NATURE GENETICS | VOLUME 37 | NUMBER 2 | FEBRUARY 2005 111 Supplementary Methods online). We also genotyped three SNPs, 001Msp (rs577001), 012Taq (rs237012) and 018Hha (rs237018) flanking 163A→G in the families from the UK, US, Finland, Romania, Norway and Northern Ireland and in the British casecontrol samples and obtained no evidence of association with T1D (Supplementary Tables 2 and 3 online). Guo et al.2 did report evidence of association from diverse ethnic groups, but the bulk of their supporting evidence came from European Americans, who would be well represented by the European American and British samples studied here (in fact, of 558 families, ∼300 directly overlap). Our results were not influenced by age-at-onset in the cases (P = 0.09, 0.47, 0.29 and 0.23 for 163A→G, 001Msp, 012Taq and 018Hha, respectively) or in the affected offspring (P = 0.87, 0.86, 0.90 and 0.37, respectively), as shown by regression analysis. Our study, with 18,132 individuals (3,007 transmissions and 7,230 cases and controls; Supplementary Table 4 online), is much larger than the two previously published studies combined. Taking into account all the results, we conclude that there is no convincing evidence for the association of the 163A→G SNP with T1D. The previous result of Guo et al.2 (P = 2.9 × 10–5) may be a false positive. In genetic association studies of common diseases, there is a very low prior probability of detecting a true positive result, given the large numbers of genes and polymorphisms in the genome, such that a P value on the order of 10–5 could still be false4–6. The problem of false positive results can be compounded by selection biases in the collection of samples, genotyping errors, population substructure and post-hoc subgroup analyses4–6. There are other explanations for the discrepant results obtained, such as complex gene-gene or geneenvironment interactions. In the first instance, however, it is necessary to attempt to exclude the possibility that the initial finding is a false positive. Both Bohren et al. and Guo et al. reported evidence of functional differences between the 55M and 55V allotypes of SUMO4 (refs. 1,2). Functional studies of candidate genes and variants are essential in the study of common diseases, but they do not solve the problem of false positives.

Seasonal variation of maternal serum vitamin D in Newfoundland and Labrador.

BACKGROUND Research has suggested that vitamin D insufficiency and deficiency is common at northern latitudes, and that vitamin D insufficiency and deficiency may be common during pregnancy. We measured the serum 25-hydroxyvitamin D (25-[OH]D) status of pregnant women across the province of Newfoundland and Labrador in both summer and winter to investigate seasonal differences, age associations, and differences in geospatial distribution across the province. METHODS We uniformly and randomly sampled blood from pregnant women in each of 79 census consolidated subdivisions across Newfoundland and Labrador from January to March 2007 and from July to September 2007. RESULTS We obtained 304 samples from the end of winter (March) and 289 samples from the end of summer (September). Mean serum 25-(OH)D concentration was 52.1 nmol/L in winter and 68.6 nmol/L in summer (P < 0.001); 89% were vitamin D insufficient in the winter and 64% in the summer (P < 0.001); 6.6% were vitamin D deficient in winter and 1.7% in summer (P = 0.003), and younger women tended to be more vitamin D insufficient in the winter than older women. The geospatial distribution of vitamin D insufficiency tends to follow a north-south distribution in the winter. CONCLUSIONS A significant proportion of pregnant women in Newfoundland and Labrador are vitamin D insufficient. Vitamin D insufficiency may have important adverse health consequences for both the mother and the fetus. Further study is necessary to address health outcomes and effects of vitamin D supplementation and lifestyle changes in this population.

Time series analysis of ultraviolet B radiation and type 1 diabetes in Newfoundland

Background:  Type 1 diabetes mellitus (T1DM) has been previously been associated with decreased levels of vitamin D. This study investigates the temporal association between average daily ultraviolet B (UVB) irradiance and T1DM in Newfoundland.

How formula feeding mothers balance risks and define themselves as ‘good mothers’

Breast feeding provides protection from many diseases and reduces health risks for both mother and child; however, a significant percentage of mothers in Newfoundland and Labrador, Canada choose to formula feed their infants from birth. In order to understand this phenomenon, qualitative research in the form of focus groups was conducted in three communities in the province in 2010. The data elicited from the research question ‘Why did you choose to formula feed your baby?’ were analysed using qualitative thematic content analysis. A major theme that arose was how these women define themselves as ‘good mothers’ in an environment where breast feeding is considered the optimal nutritional choice. It is about balancing the risks of formula feeding their infants with the needs of the family and themselves.

A qualitative study exploring factors associated with mothers’ decisions to formula-feed their infants in Newfoundland and Labrador, Canada

BackgroundBreastfeeding has numerous health benefits. In 2010, the province of Newfoundland and Labrador had the lowest breastfeeding initiation rate (64.0%) in Canada. Formula feeding is associated with well-known health risks. Exclusive formula feeding is the “cultural norm” in some regions of the province. Women appear resistant to changing their infant feeding behaviors and remain committed to their decision to formula-feed. The primary aim of this qualitative study was to examine individual factors that shaped mothers’ decisions to formula-feed their infants. Nineteen mothers who were currently formula feeding their children participated in the study.MethodsQualitative research in the form of focus groups was conducted in three communities in the province in 2010. A thematic content analysis identified the main themes that influenced mothers’ decisions to formula-feed their infants.ResultsThe main themes included issues concerning the support needed to breastfeed, the convenience associated with formula feeding, and the embarrassment surrounding breastfeeding in public.ConclusionsThese findings help to better understand why mothers choose formula feeding over breastfeeding and may help to inform the development of public health interventions targeted at this population of mothers.

Assessing Infant Feeding Attitudes of Expectant Women in a Provincial Population in Canada: Validation of the Iowa Infant Feeding Attitude Scale.

Background: Maternal attitudes to infant feeding are predictive of intent and initiation of breastfeeding. Objectives: The Iowa Infant Feeding Attitude Scale (IIFAS) has not been validated in the Canadian population. This study was conducted in Newfoundland and Labrador, a Canadian province with low breastfeeding rates. Objectives were to assess the reliability and validity of the IIFAS in expectant mothers; to compare attitudes to infant feeding in urban and rural areas; and to examine whether attitudes are associated with intent to breastfeed. Methods: The IIFAS assessment tool was administered to 793 pregnant women. Differences in the total IIFAS scores were compared between urban and rural areas. Reliability and validity analysis was conducted on the IIFAS. The receiver operating characteristic (ROC) of the IIFAS was assessed against mother’s intent to breastfeed. Results: The mean ± SD of the total IIFAS score of the overall sample was 64.0 ± 10.4. There were no significant differences in attitudes between urban (63.9 ± 10.5) and rural (64.4 ± 9.9) populations. There were significant differences in total IIFAS scores between women who intend to breastfeed (67.3 ± 8.3) and those who do not (51.6 ± 7.7), regardless of population region. The high value of the area under the curve (AUC) of the ROC (AUC = 0.92) demonstrates excellent ability of the IIFAS to predict intent to breastfeed. The internal consistency of the IIFAS was strong, with a Cronbach’s alpha greater than .80 in the overall sample. Conclusion: The IIFAS examined in this provincial population provides a valid and reliable assessment of maternal attitudes toward infant feeding. This tool could be used to identify mothers less likely to breastfeed and to inform health promotion programs.