Also within 1 month of the initial visit, BP was measured using Dynamap vital sign monitors (model BP 8800; Critikon, Inc). Measurements were taken by trained nurses. Before BP measurement, mid–upper arm circumference was measured and recorded (cm) to determine appropriate cuff size, and all children and adolescents were required to sit and rest for at least 5 minutes before applications pour les mammie sucrée BP measurement was recorded. Two measurements were taken in the right arm after a 5? and 10?minute rest. The mean of these 2 measurements was considered, but if the 2 measurements differed by ?5 mm Hg, a third measurement was taken. BP was classified according to national guidelines for children and adolescents as normal (systolic BP [SBP] and diastolic BP [DBP] <90th percentile); prehypertension (SBP or DBP ?90th to <95th percentile or BP > mm Hg to <95th percentile); and hypertension, including stage 1 and 2 (SBP and/or DBP >95th percentile). 7 If SBP was ?140 or if DBP ?90 but <100 and the child had no symptoms, he or she was included in the PMSS. If the child was symptomatic or if DBP was ?100, he or she was excluded from the study and immediately sent to the emergency department.
Diet Investigation
Dietary intake was also assessed within 1 month of the initial visit using the Block Kids 2004 food frequency questionnaire (FFQ). Children and adolescents self?reported their dietary intake using the semiquantified FFQ adapted for children. 8 The 75?item questionnaire was administered verbally and verbatim in English by the RDN or trained research assistant to each child, with a serving size visual provided for reference. 8 The RDN was available to clarify any questions posed by the children, and children were encouraged to answer all questions. Both the child and the parent were present during the administration of the FFQ for all children <18 years. Although all questions were directed toward the child, the parent was allowed to answer if the child was unable or unwilling to do so. All answers were recorded by the RDN verbatim in the electronic medical record. All FFQs were analyzed by Nutrition Quest (Berkeley, CA). Servings per day of dairy as well as calcium, vitamin D, and other micronutrient, macronutrient, and energy intakes were obtained from the FFQ analysis. Dairy?related questions inquired about milk as a beverage, milk on cereal, cheese consumed alone or as part of sandwiches or mixed dishes (eg, macaroni and cheese, pizza), and ice creams. Examples of a single serving of dairy include a 1.5?oz slice of natural cheese, 2 oz processed cheese, 1 cup frozen yogurt, 1.5 cups of ice cream, or an 8 fl oz glass or half?pint carton of dairy milk (or calcium?fortified soy milk). If able, children were asked to specify the type and fat content of their “usual” milk items in the following manner: whole, nonfat, reduced fat (2%), low fat (1%), Lactaid, soy milk, or rice milk.
Mathematical Analyses
Descriptive analyses were performed to summarize child demographic information. Continuous variables were normally distributed, and differences in continuous variables were examined using ANOVA; ? 2 tests were used with categorical variables. We used Pearson correlations to examine associations between continuous variables. Linear regression models were controlled for BMI and age, and all analyses were stratified by race. All analyses were conducted using SPSS statistical software version 24 (IBM Corp). P<0.05 was considered statistically significant. This study was originally powered to detect differences in fasting insulin levels between black and white participants (240 participants [n=120 black, n=120 white] were required to have 80% power to detect a small to medium effect size of 0.36 using a 2?group t test with a 0.05 significance level). The current study, however, is an analysis of baseline data, and to detect differences in dairy intake between black and white children, a sample size of 102 (n=51 black, n=51 white) would be required to have 80% power to detect a medium effect size of 0.50 using a 2?group t test with a significance level of 0.05.