Ensuring children are fasting for blood draws is necessary to diagnose abnormalities in glucose homeostasis. We sought to determine if serum free fatty acid (FFA) concentrations might be a useful ...marker to differentiate the fed and fasted states among children.
A total of 442 inpatient (fasting) and 323 (postglucose load) oral glucose tolerance test samples of glucose, insulin, and FFA from children (age 5-18 years) who had healthy weight, overweight, or obesity were examined by receiver operating characteristic (ROC) curve analysis to identify a cut point for nonfasting. In a cross-sectional study, we compared mean FFA and percentage of FFA values below this cut point as a function of inpatient (
= 442) versus outpatient (
= 442) setting.
The area under the curve of FFA was significantly better (
values < .001) than the area under the curve of glucose or insulin for identifying nonfasting. FFA <287 mEq/mL had 99.0% sensitivity and 98.0% specificity for nonfasting. Mean FFA was lower in outpatients than inpatients (
< .001); only 1.6% inpatient but 9.7% outpatient FFA values were consistent with nonfasting (
< .001).
Clinicians cannot assume that pediatric patients are adequately fasted on arrival for fasting blood work. On the basis of having significantly lower outpatient than inpatient FFA values and more frequently suppressed FFA, children appeared less likely to be fasting at outpatient appointments. FFA value <287 mEq/mL was a sensitive and specific cutoff for nonfasting in children that may prove clinically useful.
Few studies have assessed the accuracy of the FreeStyle Libre Pro (FLP) continuous glucose monitor for estimating plasma glucose (PG) in non‐diabetic children.
Objective
Determine the accuracy of FLP ...compared to PG during OGTT in healthy children.
Subjects
Children (7‐11.99 years) with healthy weight and overweight/obesity (n = 33; 52% male).
Methods
Participants wore the FLP before and during a 2‐hour OGTT; PG was measured at 30 minutes intervals. Potential systematic‐ and magnitude‐related biases for FLP vs PG were examined.
Results
FLP 15‐minute averages and PG were correlated at most timepoints during OGTT (r2 = 0.35‐0.69, P's < .001 for time point 30‐120 minutes) and for PG area under the curve (AUC) (r2 = 0.65, P < .0001). There were no systematic biases as assessed by Bland‐Altman analyses for FLP AUC or for FLP at each OGTT timepoint. However, for fasting glucose, a significant magnitude bias was noted (r2 = 0.38, P < .001), such that lower PG was underestimated, and higher PG was overestimated by FLP readings; further, there was poor correlation between fasting PG and FLP (r2 = 0.06, P = .22). BMIz was also associated with FLP accuracy: FLP overestimated PG in children with low BMIz and underestimated PG in those with overweight/obesity for OGTT AUC and OGTT PG at baseline, 60, and 120 minutes (all P's ≤ .015). No adverse events occurred with FLP.
Conclusions
Among children without diabetes, the FLP was well tolerated and correlated with post‐OGTT glucose, but had magnitude bias affecting fasting glucose and appeared to underestimate plasma glucose in those with overweight/obesity. These results suggest potential limitations for the utility of the FLP for research.
Background
Metabolic disease risk in youth is influenced by sedentary behaviors. Acute in‐lab studies show that, during a single day, interrupting a sedentary period with short bouts of physical ...activity improves glucometabolic outcomes.
Objective
To determine if acutely improved glucose metabolism persists after multi‐day interruptions of sitting with walking brief bouts. We hypothesized that children who underwent interrupting sitting on multiple days would demonstrate lower insulin area under the curve during an oral glucose tolerance test compared to uninterrupted sitting.
Methods
Healthy, normoglycemic children (N = 109) ages 7–11 years were randomized to one of two conditions: Control (3 h of daily Uninterrupted Sitting) or Interrupted Sitting (3‐min of moderate‐intensity walking every 30 min for 3 h daily); with dietary intake controlled through provision of foodstuffs for the entire experiment. Participants attended six consecutive daily visits at a research ambulatory unit. The primary outcome was insulin area under the curve during the oral glucose tolerance test on day 6 during interrupted or uninterrupted sitting; secondary outcomes included glucose and c‐peptide area under the curve, energy intake at a buffet meal on day 6, and free‐living activity.
Results
Among 93 children (42 uninterrupted sitting, 51 interrupted sitting), daily interrupted sitting resulted in 21% lower insulin (β = 0.102 CI:0.032–0.172, p = 0.005) and a 10% lower C‐peptide (β = 0.043, CI:0.001–0.084, p = 0.045) area under the curve. Matsuda and Glucose Effectiveness Indices were also improved (p's < 0.05). There were no group differences in energy intake or expenditure.
Conclusions
Sustained behavioral change by interrupting sedentary behaviors is a promising intervention strategy for improving metabolic risk in children.
There is growing evidence that pre-exposure prophylaxis (PrEP) prevents HIV acquisition. However, in the United States, approximately only 4% of people who could benefit from PrEP are currently ...receiving it, and it is estimated only 1 in 5 physicians has ever prescribed PrEP. We conducted a scoping review to gain an understanding of physician-identified barriers to PrEP provision. Four overarching barriers presented in the literature: Purview Paradox, Patient Financial Constraints, Risk Compensation, and Concern for ART Resistance. Considering the physician-identified barriers, we make recommendations for how physicians and students may work to increase PrEP knowledge and competence along each stage of the PrEP cascade. We recommend adopting HIV risk assessment as a standard of care, improving physician ability to identify PrEP candidates, improving physician interest and ability in encouraging PrEP uptake, and increasing utilization of continuous care management to ensure retention and adherence to PrEP.
Objective: To evaluate the accuracy and practicality of the FreeStyle Libre Pro continuous glucose monitor (CGM) during oral glucose tolerance testing (OGTT) in a nondiabetic pediatric sample.
...Background: The FreeStyle Libre Pro CGM has been found, in adults, to have acceptable accuracy compared to lab-measured glucose without requiring individual patient calibrations. No studies have assessed lab-measured glucose accuracy for this CGM in children.
Hypothesis: FreeStyle Libre Pro CGM glucose will not differ significantly from lab-measured plasma glucose during OGTT in youth.
Methods: Healthy weight and overweight volunteers (n =8; 63% male), aged 7-11y wore FreeStyle Libre Pro Flash CGM for 6 days, with a 2-hour OGTT (1.75mg/kg, max 75g) on day 6. Laboratory (Cobas E6000, Roche) plasma glucose was measured at 30min intervals for 120min, and compared with the 15min average simultaneously obtained CGM glucose value. Glucose at each timepoint and Area Under the Curve (AUC) for CGM and lab-measured glucose were compared using paired t-tests. A correlation coefficient was calculated for each timepoint. Potential systematic errors were examined using Bland-Altman analyses.
Results: AUC for CGM and lab glucose were well correlated (r= 0.91, p=0.006) and did not differ in mean value (p=0.84). CGM and lab glucose readings were not significantly different at any timepoint (all p’s>0.18). There were no significant systematic or magnitude errors as assessed by Bland-Altman analyses at any timepoint. No adverse events occurred with CGM use and all participants considered the device easy to wear.
Conclusions: The Freestyle Libre Pro CGM device was well tolerated and, even without individual calibration, provided quantitatively similar glucose readings during OGTT for healthy weight and overweight children when compared to lab-measured glucose. If confirmed in larger studies, this CGM may provide adjunctive data during evaluations of glucose excursions that may be useful for pediatric clinical care and research.
Disclosure
N. Ghane: None. M. Broadney: None. S.M. Collins: None. E.K. Davis: None. S. Brady: None. J.A. Yanovski: Research Support; Self; Rhythm Pharmaceuticals Inc., Zafgen.
Background
Many studies show a correlation between short sleep duration and obesity/insulin resistance. One hypothesis for this association is that shortened sleep causes increased energy intake ...(EI). In some studies, experimentally reduced sleep duration has been found to increase total EI. There are mixed findings about the effects of habitual and acute short sleep on the macronutrient content of consumed meals. Additionally, there are few pediatric studies with objectively measured sleep duration (e.g. using actigraphy). Therefore, we aimed to determine if an acute sleep change was associated with greater total EI, altered macronutrient intake, or altered insulin sensitivity in children.
Methods
Healthy weight and overweight volunteers (n=18, 44% male), aged 7-11 years wore ActiGraph activity monitors for six consecutive 24 hour periods to determine nightly sleep duration. Volunteers were given no direction regarding sleep for the week. On day six, children underwent a standardized oral glucose tolerance test (OGTT) (1.75g/kg, max 75g) after which total EI (kcal) and macronutrient composition (% of total EI) were measured during a lunchtime laboratory test meal (>10,000 kcal; ~12% protein, 32% fat, 56% CHO). Subjects were directed to eat as much as they wanted. Acute change in sleep was calculated by subtracting each participant’s average nightly total sleep time over the entire week from their total sleep time on the fifth night (i.e., night before the test meal). Linear regressions examined associations of acute change in sleep with insulin AUC during OGTT, total EI, % CHO, % fat, and ratio of %CHO to %fat intake.
Results
Controlling for daily predicted energy needs and physical activity level, acute change in sleep (mean of 27.5 minutes less than average) was not significantly associated with total EI (p=0.58). However, the %CHO trended toward a significant negative correlation (r=-0.47, p=0.05) and %fat was positively associated (r=0.50, p=0.036) with acute change in sleep such that the %CHO to %fat intake ratio was greater in those with greater sleep deficit (p=0.039). Additionally, controlling for BMI-z score, basal insulin, and age, greater sleep deficit was associated with increased insulin AUC during the OGTT (p=0.001).
Discussion
Contrary to some previous experimental data, acute sleep deficit had no significant association with total EI; however, acute sleep deficit was associated with increased relative carbohydrate intake. Acute sleep deficit was also associated with decreased relative fat intake, a known satiating macronutrient. These data also suggest an acute decrease in insulin sensitivity associated with sleep deficit. All three mechanisms could explain or exacerbate the increased prevalence of obesity and metabolic abnormalities in children with short sleep duration and therefore, provide support for sleep-associated adjunctive treatment for such children.
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