Dietary fiber and the glycemic index : a background paper for the Nordic Nutrition Recommendations 2012

The aim of this study is to review recent data on dietary fiber (DF) and the glycemic index (GI), with special focus on studies from the Nordic countries regarding cardiometabolic risk factors, type 2 diabetes, cardiovascular disease, cancer, and total mortality. In this study, recent guidelines and scientific background papers or updates on older reports on DF and GI published between 2000 and 2011 from the US, EU, WHO, and the World Cancer Research Fund were reviewed, as well as prospective cohort and intervention studies carried out in the Nordic countries. All of the reports support the role for fiber-rich foods and DF as an important part of a healthy diet. All of the five identified Nordic papers found protective associations between high intake of DF and health outcomes; lower risk of cardiovascular disease, type 2 diabetes, colorectal and breast cancer. None of the reports and few of the Nordic papers found clear evidence for the GI in prevention of risk factors or diseases in healthy populations, although association was found in sub-groups, e.g. overweight and obese individuals and suggestive for prevention of type 2 diabetes. It was concluded that DF is associated with decreased risk of different chronic diseases and metabolic conditions. There is not enough evidence that choosing foods with low GI will decrease the risk of chronic diseases in the population overall. However, there is suggestive evidence that ranking food based on their GI might be of use for overweight and obese individuals. Issues regarding methodology, validity and practicality of the GI remain to be clarified

Development of a dietary screening questionnaire to predict excessive weight gain in pregnancy.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadExcessive gestational weight gain (GWG) is a risk factor for several adverse pregnancy outcomes, including macrosomia. Diet is one of the few modifiable risk factors identified. However, most dietary assessment methods are impractical for use in maternal care. This study evaluated whether a short dietary screening questionnaire could be used as a predictor of excessive GWG in a cohort of Icelandic women. The dietary data were collected in gestational weeks 11-14, using a 40-item food frequency screening questionnaire. The dietary data were transformed into 13 predefined dietary risk factors for an inadequate diet. Stepwise backward elimination was used to identify a reduced set of factors that best predicted excessive GWG. This set of variables was then used to calculate a combined dietary risk score (range 0-5). Information regarding outcomes, GWG (n = 1,326) and birth weight (n = 1,651), was extracted from maternal hospital records. In total, 36% had excessive GWG (Icelandic criteria), and 5% of infants were macrosomic (≥4,500 g). A high dietary risk score (characterized by a nonvaried diet, nonadequate frequency of consumption of fruits/vegetables, dairy, and whole grain intake, and excessive intake of sugar/artificially sweetened beverages and dairy) was associated with a higher risk of excessive GWG. Women with a high (≥4) versus low (≤2) risk score had higher risk of excessive GWG (relative risk = 1.23, 95% confidence interval, CI [1.002, 1.50]) and higher odds of delivering a macrosomic offspring (odds ratio = 2.20, 95% CI [1.14, 4.25]). The results indicate that asking simple questions about women's dietary intake early in pregnancy could identify women who should be prioritized for further dietary counselling and support.UoI Research Fund Technology Development Fund/The Icelandic Centre for Research (RANNIS

Vitamin D status and association with gestational diabetes mellitus in a pregnant cohort in Iceland.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Vitamin D deficiency has been associated with an increased risk of gestational diabetes mellitus (GDM), one of the most common pregnancy complications. The vitamin D status has never previously been studied in pregnant women in Iceland. Objective: The aim of this research study was to evaluate the vitamin D status of an Icelandic cohort of pregnant women and the association between the vitamin D status and the GDM incidence. Design: Subjects included pregnant women (n = 938) who attended their first ultrasound appointment, during gestational weeks 11-14, between October 2017 and March 2018. The use of supplements containing vitamin D over the previous 3 months, height, pre-pregnancy weight, and social status were assessed using a questionnaire, and blood samples were drawn for analyzing the serum 25‑hydroxyvitamin D (25OHD) concentration. Information regarding the incidence of GDM later in pregnancy was collected from medical records. Results: The mean ± standard deviation of the serum 25OHD (S-25OHD) concentration in this cohort was 63±24 nmol/L. The proportion of women with an S-25OHD concentration of ≥ 50 nmol/L (which is considered adequate) was 70%, whereas 25% had concentrations between 30 and 49.9 nmol/L (insufficient) and 5% had concentrations < 30 nmol/L (deficient). The majority of women (n = 766, 82%) used supplements containing vitamin D on a daily basis. A gradual decrease in the proportion of women diagnosed with GDM was reported with increasing S-25OHD concentrations, going from 17.8% in the group with S-25OHD concentrations < 30 nmol/L to 12.8% in the group with S-25OHD concentrations ≥75 nmol/L; however, the association was not significant (P for trend = 0.11). Conclusion: Approximately one-third of this cohort had S-25OHD concentrations below adequate levels (< 50 nmol/L) during the first trimester of pregnancy, which may suggest that necessary action must be taken to increase their vitamin D levels. No clear association was observed between the vitamin D status and GDM in this study. Keywords: cod liver oil; gestational diabetes mellitus; nutritional status; pregnancy; supplements; vitamin D.University of Iceland Research Fund Science Fund of Landspitali National University Hospita

A Case of Complete Scotoma Following Intake of Conjugated Linoleic Acid Supplement

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Relationship between size at birth and hypertension in a genetically homogeneous population of high birth weight

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: To investigate the association between birth size and hypertension within a genetically homogeneous population of high birth weight. DESIGN: Cohort-study with retrospectively collected data on size at birth. SUBJECTS AND SETTING: The study included 4601 men and women born 1914-1935 in Reykjavik, Iceland, who participated in the Reykjavik Study of the Icelandic Heart Association. MAIN OUTCOME MEASURES: Birth size measurements, adult blood pressure (BP) and body mass index (BMI), and family history of hypertension. RESULTS: Birth weight was inversely related to hypertension in adulthood in women (P for trend 0.05). For women with an adult BMI > 26 kg/m2, the odds ratio for hypertension for those born weighing 3.75 kg. The association was only significant in women without a family history of hypertension. CONCLUSIONS: An inverse association between size at birth and adult hypertension was seen in a population of greater birth size than has previously been investigated. The relation was strongest among women born small who were overweight in adulthood, and for those without a family history of hypertension. The results support the hypothesis that the association between birth weight and hypertension is not of genetic origin only. The large birth size of Icelanders might be protective and partly explain the lower mean systolic blood pressure in Iceland than in related nations

Weight gain in women of normal weight before pregnancy: complications in pregnancy or delivery and birth outcome.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: To investigate the relation between gestational weight gain in women of normal prepregnant weight and complications during pregnancy and delivery in a population with high gestational weight gain and birth weight. METHODS: Healthy women (n = 615) of normal weight before pregnancy (body mass index 19.5-25.5 kg/m(2)) were randomly selected. Maternity records gave information on age, height, prepregnant weight, gestational weight gain, parity, smoking, gestational hypertension and diabetes, preeclampsia, delivery complications, and infants' birth size and health. RESULTS: The mean weight gain in pregnancy was 16.8 +/- 4.9 kg (mean +/- standard deviation). A total of 26.4% of the women had complications, either in pregnancy (9.1%) or delivery (17.3%). Women gaining weight according to the recommendation of the Institute of Medicine (11.5-16.0 kg) had lower frequency of pregnancy-delivery complications than women gaining more than 20.0 kg (P =.017), but did not differ significantly from those gaining 16-20 kg (P >.05). When dividing weight gain in pregnancy into quintiles, a relative risk of 2.69 (95% confidence interval 1.01, 7.18, P =.048) was found for complications in pregnancy in the fourth quintile (17.9-20.8 kg), using the second quintile as reference (12.5-15.5 kg). The mean birth weight was 3778 +/- 496 g. A low weight gain in pregnancy (less than 11.5 kg) was associated with an increased frequency of infants weighing less than 3500 g at birth (P <.01). CONCLUSION: A gestational weight gain of 11.5-16.0 kg (Institute of Medicine recommendation) for women of normal prepregnant weight is related to the lowest risk for pregnancy-delivery complications. In the population studied, the upper limit might be higher (up to 18 kg), and low weight gain should be avoided to optimize birth outcome

Size at birth and coronary artery disease in a population with high birth weight

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldBACKGROUND: Epidemiologic studies suggest a link between fetal and childhood growth and later coronary artery disease (CAD). The influence of adult body size on the relation between birth size and CAD has not been thoroughly studied. OBJECTIVE: We investigated the association between birth and adult sizes and CAD within a population with higher birth weight and a lower incidence of and mortality rate from CAD than those seen in other Scandinavian populations. DESIGN: Fatal or nonfatal CAD was ascertained in 2399 men and 2376 women born in the Greater Reykjavik area between 1914 and 1935. Birth size was obtained from the National Archives. Anthropometric measurements in adults were obtained from the randomized prospective Reykjavik Study. RESULTS: CAD was inversely related to birth length (P for trend = 0.029) in men but was not significantly related to birth weight or ponderal index (kg/m(3)). In men who were born short ( 180.5 cm), the odds ratios (95% CI) for CAD were 1.9 (1.1, 3.1) and 2.2 (1.2, 4.0), respectively, when compared with men in the reference group (those born 52.5-54.0 cm long). A U-shaped relation between birth size and CAD was found for women. CONCLUSIONS: Size at birth has an effect on CAD, but the effect is modified by adult body size. This confirms that environmental factors operate in both the prenatal and postnatal periods with regard to the development of CAD. The large birth size seen among Icelanders may explain the lower incidence and mortality rate of CAD in Iceland than are seen in other white populations

Size at birth and glucose intolerance in a relatively genetically homogeneous, high-birth weight population

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldBACKGROUND: The results of epidemiologic studies have linked birth size to adult glucose intolerance. OBJECTIVE: We investigated this association in a genetically homogeneous population with higher birth weights and a lower prevalence of type 2 diabetes than previously studied. DESIGN: The subjects were 2362 men and 2286 women aged 33-65 y. Size at birth was obtained from the National Archives of Iceland. Data for adult anthropometry, fasting blood glucose, and blood glucose after an oral glucose load came from the randomized prospective Reykjavík Study. RESULTS: Postchallenge glucose concentrations were inversely related to birth weight and length in men and inversely related to birth weight and ponderal index in women (P < 0.001). This association was mainly found among those within the highest one-third of adult body mass index values. In men, the prevalence of dysglycemia was lower with increasing weight (P = 0.04) and length (P = 0.003) at birth but there was no relation of dysglycemia to ponderal index. For women, there was no linear trend for dysglycemia in relation to size at birth but the relation with birth length was U shaped. CONCLUSIONS: Greater birth weight and length appear to offer a protective effect against glucose intolerance. Adult overweight or obesity enhances the risk associated with low birth weight and length. Because the population studied has higher birth weights and a lower prevalence of type 2 diabetes than are found in neighboring countries, it is possible that decreasing the number of low-birth weight infants might help to stem the increasing prevalence of type 2 diabetes worldwide

Relationship between size at birth and hypertension in a genetically homogeneous population of high birth weight

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: To investigate the association between birth size and hypertension within a genetically homogeneous population of high birth weight. DESIGN: Cohort-study with retrospectively collected data on size at birth. SUBJECTS AND SETTING: The study included 4601 men and women born 1914-1935 in Reykjavik, Iceland, who participated in the Reykjavik Study of the Icelandic Heart Association. MAIN OUTCOME MEASURES: Birth size measurements, adult blood pressure (BP) and body mass index (BMI), and family history of hypertension. RESULTS: Birth weight was inversely related to hypertension in adulthood in women (P for trend 0.05). For women with an adult BMI > 26 kg/m2, the odds ratio for hypertension for those born weighing 3.75 kg. The association was only significant in women without a family history of hypertension. CONCLUSIONS: An inverse association between size at birth and adult hypertension was seen in a population of greater birth size than has previously been investigated. The relation was strongest among women born small who were overweight in adulthood, and for those without a family history of hypertension. The results support the hypothesis that the association between birth weight and hypertension is not of genetic origin only. The large birth size of Icelanders might be protective and partly explain the lower mean systolic blood pressure in Iceland than in related nations

Size at birth and coronary artery disease in a population with high birth weight

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldBACKGROUND: Epidemiologic studies suggest a link between fetal and childhood growth and later coronary artery disease (CAD). The influence of adult body size on the relation between birth size and CAD has not been thoroughly studied. OBJECTIVE: We investigated the association between birth and adult sizes and CAD within a population with higher birth weight and a lower incidence of and mortality rate from CAD than those seen in other Scandinavian populations. DESIGN: Fatal or nonfatal CAD was ascertained in 2399 men and 2376 women born in the Greater Reykjavik area between 1914 and 1935. Birth size was obtained from the National Archives. Anthropometric measurements in adults were obtained from the randomized prospective Reykjavik Study. RESULTS: CAD was inversely related to birth length (P for trend = 0.029) in men but was not significantly related to birth weight or ponderal index (kg/m(3)). In men who were born short ( 180.5 cm), the odds ratios (95% CI) for CAD were 1.9 (1.1, 3.1) and 2.2 (1.2, 4.0), respectively, when compared with men in the reference group (those born 52.5-54.0 cm long). A U-shaped relation between birth size and CAD was found for women. CONCLUSIONS: Size at birth has an effect on CAD, but the effect is modified by adult body size. This confirms that environmental factors operate in both the prenatal and postnatal periods with regard to the development of CAD. The large birth size seen among Icelanders may explain the lower incidence and mortality rate of CAD in Iceland than are seen in other white populations