Barend J. C. Middelkoop

Prevalence of vitamin D deficiency among Turkish, Moroccan, Indian and sub-Sahara African populations in Europe and their countries of origin: an overview

SummaryVitamin D status of nonwestern immigrants in Europe was poor. Vitamin D status of nonwestern populations in their countries of origin varied, being either similar to the immigrant populations in Europe or higher than in European indigenous populations. Vitamin D concentrations in nonwestern immigrant populations should be improved.PurposeThe higher the latitude, the less vitamin D is produced in the skin. Most European countries are located at higher latitudes than the countries of origin of their nonwestern immigrants. Our aim was to compare the serum 25-hydroxyvitamin D (25(OH)D) concentration of nonwestern immigrant populations with those of the population in their country of origin, and the indigenous population of the country they migrated to.MethodsWe performed literature searches in the “PubMed” and “Embase” databases, restricted to 1990 and later. The search profile consisted of terms referring to vitamin D or vitamin D deficiency, prevalence or cross-sectional studies, and countries or ethnicity. Titles and abstracts were reviewed to identify studies on population-based mean serum 25(OH)D concentrations among Turkish, Moroccan, Indian, and sub-Sahara African populations in Europe, Turkey, Morocco, India, and sub-Sahara Africa.ResultsThe vitamin D status of immigrant populations in Europe was poor compared to the indigenous European populations. The vitamin D status of studied populations in Turkey and India varied and was either similar to the immigrant populations in Europe (low) or similar to or even higher than the indigenous European populations (high).ConclusionsIn addition to observed negative consequences of low serum 25(OH)D concentrations among nonwestern populations, this overview indicates that vitamin D status in nonwestern immigrant populations should be improved. The most efficacious strategy should be the subject of further study.

Trends in overweight and obesity prevalence in Dutch, Turkish, Moroccan and Surinamese South Asian children in the Netherlands

Objective: To determine trends in the prevalence of overweight and obesity in children in The Hague (the Netherlands) from 1999 through 2007. Design: Population-based study of a series of cross-sectional assessments of height and weight from electronic health records. Setting: Child Health Care (Municipal Health Service), The Hague. Participants: 50 961 children aged 3–16 years, with Dutch (59%), Turkish (17%), Moroccan (13%) or Surinamese South Asian (11%) ethnicity, representative of the four major ethnic groups in The Hague, with 85 234 weight and height measurements recorded in 1999–2007. Main outcome measures: (Trends in) the prevalence of overweight (excluding obesity) and obesity as defined by the International Obesity Taskforce cut-off points, using logistic regression with year as independent variable. Results: From 1999 through 2007 there was a decrease in the prevalence of overweight in Dutch girls from 12.6% to 10.9% (OR 0.96; 95% CI 0.95 to 0.98) and an increase in Turkish boys from 14.6% to 21.4% (OR 1.08; 95% CI 1.04 to 1.11). Obesity prevalence rose significantly in Turkish boys from 7.9% to 13.1% (OR 1.04; 95% CI 1.01 to 1.06) and in Turkish girls from 8.0% to 10.7% (OR 1.04; 95% CI 1.01 to 1.08). Dutch boys, and Moroccan and Surinamese South Asian boys and girls showed no significant trends. Conclusions: The declining prevalence of overweight in Dutch girls may indicate reversal of previous trends in the Netherlands. However, in Turkish children overweight prevalence and obesity is high and increasing. Further public health action is necessary, especially for Turkish children.

Fatty fish and supplements are the greatest modifiable contributors to the serum 25-hydroxyvitamin D concentration in a multiethnic population

Objective  Because vitamin D synthesis is lower in a heavily pigmented skin than in a lighter skin, the relative contribution of determinants to the vitamin D concentration might differ between ethnic groups. The aim of this study was to assess the prevalence of vitamin D deficiency and the relative contribution of vitamin D consumption and exposure to sunlight to the vitamin D concentration in a multiethnic population.

Measuring determinants of implementation behavior: psychometric properties of a questionnaire based on the theoretical domains framework

BackgroundTo be able to design effective strategies to improve healthcare professionals’ implementation behaviors, a valid and reliable questionnaire is needed to assess potential implementation determinants. The present study describes the development of the Determinants of Implementation Behavior Questionnaire (DIBQ) and investigates the reliability and validity of this Theoretical Domains Framework (TDF)-based questionnaire.MethodsThe DIBQ was developed to measure the potential behavioral determinants of the 12-domain version of the TDF (Michie et al., 2005). We identified existing questionnaires including items assessing constructs within TDF domains and developed new items where needed. Confirmatory factor analysis was used to examine whether the predefined structure of the TDF-based questionnaire was supported by the data. Cronbach’s alpha was calculated to assess internal consistency reliability of the questionnaire, and domains’ discriminant validity was investigated.ResultsWe developed an initial questionnaire containing 100 items assessing 12 domains. Results obtained from confirmatory factor analysis and Cronbach’s alpha resulted in the final questionnaire consisting of 93 items assessing 18 domains, explaining 63.3% of the variance, and internal consistency reliability values ranging from .68 to .93. Domains demonstrated good discriminant validity, although the domains ‘Knowledge’ and ‘Skills’ and the domains ‘Skills’ and ‘Social/professional role and identity’ were highly correlated.ConclusionsWe have developed a valid and reliable questionnaire that can be used to assess potential determinants of healthcare professional implementation behavior following the theoretical domains of the TDF. The DIBQ can be used by researchers and practitioners who are interested in identifying determinants of implementation behaviors in order to be able to develop effective strategies to improve healthcare professionals’ implementation behaviors. Furthermore, the findings provide a novel validation of the TDF and indicate that the domain ‘Environmental context and resources’ might be divided into several environment-related domains.

Declining and stabilising trends in prevalence of overweight and obesity in Dutch, Turkish, Moroccan and South Asian children 3–16 years of age between 1999 and 2011 in the Netherlands

Objective In many developed countries, overweight and obesity prevalence seems to stabilise. The aim of this study was to determine trends between 1999 and 2011 in overweight and obesity prevalence, and mean Body Mass Index (BMI) z-score in Dutch, Turkish, Moroccan and Surinamese South Asian children in the Netherlands. Design A cross-sectional population-based study with 136 080 measurements of height and weight of 73 290 children aged 3–16 years. BMI class and BMI z-score were determined with the latest International Obesity Taskforce (IOTF) criteria, with overweight defined as an adult BMI equivalent ≥25 and obesity ≥30. Time trends per year were analysed using logistic and linear regression analyses. Results The prevalence of overweight in Dutch children declined from 13% to 11% (OR 0.960; 95% CI 0.954 to 0.965), but increased in Turkish children from 25% to 32% (OR 1.028; 95% CI 1.020 to 1.036). In Moroccan and Surinamese South Asian children, overweight rates were stable, but obesity prevalence decreased (OR 0.973; 95% CI 0.957 to 0.989, OR 0.964; 95% CI 0.943 to 0.985, respectively) as well as the mean BMI z-score (B=−0.010; 95% CI −0.014 to −0.006, B=−0.010; 95% CI −0.016 to −0.004). In Turkish children, trends limited to the period 2007–2011 showed no statistically significant relationship for all outcome measures. Conclusions The decrease in obesity prevalence in Dutch, Moroccan and Surinamese South Asian children suggests that overweight children became less adipose. The stabilising trend in overweight and obesity prevalence in Turkish children since 2007 may signify a levelling off for this ethnic group.

Neonatal anthropometry: thin-fat phenotype in fourth to fifth generation south Asian neonates in Surinam

We assessed whether the earlier described ‘thin–fat phenotype’ is present in Surinam South Asian babies of the fourth to fifth generation after migration from India. In this observational study we collected data from 39 South Asian term neonates and their mothers in Paramaribo, Surinam. We compared the following data with data from an earlier study in Southampton, UK (338 neonates) and in Pune, India (631 neonates): maternal body mass index, neonatal weight, length, head, mid-upper arm and abdominal circumferences and subscapular skinfold thickness. The mothers in Paramaribo were older than the Southampton mothers; their body mass index was comparable. Mean birth weight was 3159 g (Southampton: 3494 g; Pune: 2666 g). Compared with Southampton babies, the Paramaribo babies were smaller in nearly all body measurements, the smallest being abdominal circumference at the umbilicus level (s.d. score: −1.62; 95% confidence interval (CI): −2.07 to −1.16) and mid-upper arm circumference (s.d. score: −1.08; 95% CI: −1.46 to −0.69). In contrast, subscapular skinfold thickness was similar (s.d. score: +0.08; 95% CI: −0.24 to +0.55). Except for subscapular skinfold thickness and length, all neonatal measurements were intermediate between those from Southampton and Pune. The thin–fat phenotype is preserved in Surinam South Asian neonates of the fourth to fifth generation after migration from India.

Factors Influencing Primary Health Care Professionals’ Physical Activity Promotion Behaviors: A Systematic Review

BackgroundDespite the promising findings related to the efficacy of interventions aimed at promoting physical activity (PA) in primary health care (PHC), the translation of these interventions to PHC practice does not always happen as desired.PurposeTo help understand why efficacious PHC-based PA interventions are not effectively translated to practice, this study systematically reviewed the literature on factors influencing PHC professionals’ PA promotion practices.MethodLiterature searches were conducted in Web of Science, PubMed, and PsycINFO for peer-reviewed articles published in English from 1990 onwards. Studies were included that met the following criteria: (1) involving PHC-based PA interventions, and (2) reporting factors influencing PHC professionals’ PA promotion behaviors. Two researchers independently screened studies and extracted data. A narrative synthesis using thematic analysis was conducted to identify factors.ResultsOf the 4,469 identified articles, 59 were included in the review. Factors were identified by qualitative methods, barrier/facilitator ratings, and the examination of the relationship between factors and PA promotion, and the effectiveness of introduction strategies. Many factors related to the development, delivery, and effects of the innovation, the sociopolitical and organizational culture, resources, and support, patient and PHC professional characteristics, and innovation strategies were identified as potential influences on PHC professionals’ PA promotion practices. However, the lack of evidence on the relationship between factors and PA promotion indicated insufficient evidence on PA promotion determinants.ConclusionThis extensive overview of potential factors can inform intervention developers and implementers on which factors may play a role when introducing PA interventions in PHC. Future research should further investigate relationships between factors and PA promotion, which should be guided by qualitative in-depth knowledge on influencing factors.

Intensive lifestyle intervention in general practice to prevent type 2 diabetes among 18 to 60-year-old South Asians: 1-year effects on the weight status and metabolic profile of participants in a randomized controlled trial.

Aim To study 1-year effectiveness of an intensive, culturally targeted lifestyle intervention in general practice for weight status and metabolic profile of South-Asians at risk of type 2 diabetes. Methods 536 South-Asians at risk of type 2 diabetes were randomized to an intervention (n = 283) or control (n = 253) group. The intervention, which was targeted culturally to the South-Asian population, consisted of individual lifestyle counselling, a family session, cooking classes, and supervised physical activity programme. All components of the intervention were carried out by professionals as part of their daily clinical practice. The control group received generic lifestyle advice. Change in weight status and metabolic profile were assessed after 1 year. Results After 1 year, 201 participants were lost to follow-up. Remaining participants in intervention (n = 177) and control (n = 158) group had similar baseline characteristics. Weight loss in the intervention group was 0.2±3.3 kg, weight gain in the control group was 0.4±3.1 kg (p = 0.08). Changes in other weight-related measurements did not differ significantly between groups. Furthermore, there were no differences between groups in changes of metabolic profile. All results remained similar after repeating analyses in a multiple imputed dataset. Discussion An intensive, culturally targeted, lifestyle intervention of 1 year did not improve weight status and metabolic profile of South-Asians at risk of type 2 diabetes. The laborious recruitment, high drop-out, and lack of effectiveness emphasise the difficulty of realising health benefits in practice and suggest that this strategy might not be the optimal approach for this population. Trial Registration Nederlands Trial Register NTR1499

Feasibility and effectiveness of a targeted diabetes prevention program for 18 to 60-year-old South Asian migrants: design and methods of the DH!AAN study

BackgroundSouth Asian migrants are at particularly high risk of type 2 diabetes. Previous studies have shown that intensive lifestyle interventions may prevent the onset of diabetes. Such interventions have not been culturally adapted and evaluated among South Asians in industrialized countries. Therefore, we have set up a randomized controlled trial to study the effectiveness of a targeted lifestyle intervention for the risk of type 2 diabetes and cardiovascular risk factors among 18 to 60-year-old Hindustani Surinamese (South Asians) in The Hague, the Netherlands. Here we present the study design and describe the characteristics of those recruited.MethodsBetween May 18, 2009 and October 11, 2010, we screened 2307 Hindustani Surinamese (18–60 years old) living in The Hague. We sent invitations to participate to those who had an impaired fasting glucose of 5.6-6.9 mmol/l, an impaired glucose tolerance of 7.8-11.0 mmol/L, a glycated hemoglobin level of 6.0% or more and/or a value of 2.39 or more for the homeostasis model assessment of estimated insulin resistance. In total, 536 people (56.1% of those eligible) participated. People with a higher level of education and a family history of type 2 diabetes were more likely to participate. The control and intervention groups were similar with regard to important background characteristics. The intervention group will receive a culturally targeted intervention consisting of dietary counseling using motivational interviewing and a supervised physical activity program. The control group will receive generic lifestyle advice. To determine the effectiveness, a physical examination (anthropometrics, cardiorespiratory test, lipid profile, and measures of oral glucose tolerance, glycated hemoglobin, and insulin) and interview (physical activity, diet, quality of life, and intermediate outcomes) were carried out at baseline and will be repeated at 1 year and 2 years. The process and the costs will be evaluated.DiscussionThis trial will provide insight into the feasibility and effectiveness of a targeted, intensive, lifestyle intervention for the risk of type 2 diabetes and cardiovascular risk factors among 18 to 60-year-old South Asians.Trial registrationDutch Trial Register: NTR1499

Factors influencing the adoption, implementation, and continuation of physical activity interventions in primary health care: a Delphi study.

BackgroundThe introduction of efficacious physical activity interventions in primary health care is a complex process. Understanding factors influencing the process can enhance the development of effective introduction strategies. This Delphi study aimed to identify factors most relevant for the adoption, implementation, and continuation of physical activity interventions in primary health care by examining experts’ opinions on the importance and changeability of factors previously identified as potentially relevant for the process.MethodsIn the first round, 44 experts scored factors on their importance for each stage of the introduction process, as well as on their changeability. In the second round, the same experts received a questionnaire containing a reduced list of factors, based on the first-round results. They were asked to indicate their top-10 most important factors for each stage, and to re-rate factors’ changeability. Thirty-seven experts completed this round.ResultsMost important factors could be identified for each stage. Some factors were found important for a specific stage, e.g., the presence of intervention champions within the organization (adoption), provider knowledge (implementation), and the intervention’s sustainability (continuation), while others were perceived important for all stages, i.e., the intervention’s financial feasibility, the intervention’s accessibility to the target group, and time to deliver the intervention. The majority of most important factors was perceived changeable. However, for some factors no consensus could be reached regarding their changeability.ConclusionsThis study identified general and stage-specific factors relevant for the introduction of physical activity interventions in primary health care. It emphasizes the importance of taking these factors into account when designing introduction strategies, and of giving special attention to the distinct stages of the process. Due to lack of consensus on the changeability of most important factors, the extent to which these factors can be influenced by introduction strategies remains unclear.