A mixed-methods study on the association of six-month predominant breastfeeding with socioecological factors and COVID-19 among experienced breastfeeding women in Hong Kong.

BACKGROUND: In the past decade, various breastfeeding policies were implemented in Hong Kong, including changes in perinatal guidelines in public hospitals, adoption of the Baby-Friendly Hospital Initiative (BFHI), provision of guidelines for the marketing of formula milk, penalisation of discrimination towards breastfeeding, and extension of the statutory maternity leave. Meanwhile, the COVID-19 pandemic brought new challenges and opportunities to breastfeeding practices. Infection control measures in public hospitals included the cancellation of antenatal classes, hospital tours, and postnatal classes; suspension of perinatal visiting periods; and compulsory separation of COVID-19 positive mothers from newborns. In addition, work-from-home policies were widely implemented. This study aimed to identify the associated factors of six-month predominant breastfeeding (PBF), and to evaluate the impact of COVID-19 on breastfeeding practice. METHODS: This study was conducted from 1 March 2021 to 7 April 2021 using a mixed-methods approach. An electronic questionnaire was distributed to members of breastfeeding or parenting groups who have had breastfeeding experience in the past 10 yrs. Logistic and linear regression analyses were conducted to identify factors associated with six-month PBF both in general and during the pandemic period. A qualitative content analysis was conducted using an inductive approach. RESULTS: The study included 793 participants. Giving birth in a public hospital (OR 2.21; 95% CI 1.46, 3.34) and breastfeeding support from family and friends (OR 1.28; 95% CI 1.05, 1.57) were significantly associated with six-month PBF, even during COVID-19. Factors associated with the self-rated impact of COVID-19 on breastfeeding include working from home, the perceived immunological benefits of breastfeeding, and the wish to avoid breastfeeding or expressing breast milk in public premises. Furthermore, breastfeeding practice in public hospitals was more likely to be affected by the busyness of staff, while private hospitals had worse rooming-in practices and staff who had inadequate breastfeeding knowledge. CONCLUSIONS: Giving birth in a public hospital and having breastfeeding support from family and friends were associated with six-month PBF. Furthermore, COVID-19 in Hong Kong had an overall positive impact on six-month PBF. Further studies should investigate the impact of hospital practices and the COVID-19 pandemic on breastfeeding behaviours.

Specific IgG and IgA of common foods in Chinese children with eczema: friend or foe.

BACKGROUND: Specific immunoglobulins G and A (IgG and IgA) for common food items have been extensively measured as surrogate markers of food allergy, and dietary avoidance based on the test results advocated. AIM: We reviewed the prevalence of specific food IgG and IgA in children with eczema and evaluated outcome of dietary avoidance in these children. METHODS: Specific immunoglobulins of 96 food items were measured for 30 consecutive atopic dermatitis (AD) patients and disease severity [SCORing atopic dermatitis (SCORAD) and Nottingham eczema severity score (NESS)], Children Dermatology Life Quality Index (CDLQI), skin hydration (SH), transepidermal water loss (TEWL), topical corticosteroid and oral antihistamine usage were evaluated. Twenty seven of these patients received dietary avoidance advice based on IgG and IgA data. General acceptability of treatment (GAT) was documented at the end of 3 months. RESULTS: There were generally no correlations among levels of IgG or IgA of the 96 food items and disease severity, quality of life, SH or TEWL. Two-third patients reported very good or good and one-third reported fair or poor GAT following dietary avoidance advice. There was no difference in any clinical parameters between the two groups following dietary avoidance. Patient with lower sunflower seed IgA (p = 0.043), casein IgG (p = 0.041), milk IgG (p = 0.037) or whey IgG (p = 0.014) had improved SCORAD and objective SCORAD following dietary advice. CONCLUSION: Children with AD are sensitized to many food allergens via IgG and IgA mechanisms. Levels of food IgG or IgA do not seem to correlate with any clinical parameters in AD. Subjectively, two third of patients accepted dietary manipulations as very good or good for their AD. Objectively, dietary avoidance had few clinical effects on the clinical parameters. Sensitization should not be generalized to mean allergy to common food.

Effects of diet and exercise on obesity-related vascular dysfunction in children.

BACKGROUND: The prevalence of obesity in both adults and children is increasing rapidly. Obesity in children is independently associated with arterial endothelial dysfunction and wall thickening, key early events in atherogenesis that precede plaque formation. METHODS AND RESULTS: To evaluate the reversibility of obesity-related arterial dysfunction and carotid intima-media thickening by dietary and/or exercise intervention programs, 82 overweight children (body mass index, 25+/-3), 9 to 12 years of age, were randomly assigned to dietary modification only or diet plus a supervised structured exercise program for 6 weeks and subsequently for 1 year. The prospectively defined primary end points were ultrasound-derived arterial endothelial function (endothelium-dependent dilation) of the brachial artery and intima-media thickness of common carotid artery. At 6 weeks, both interventions were associated with decreased waist-hip ratio (P<0.02) and cholesterol level (P<0.05) as well as improved arterial endothelial function. Diet and exercise together were associated with a significantly greater improvement in endothelial function than diet alone (P=0.01). At 1 year, there was significantly less thickening of the carotid wall (P<0.001) as well as persistent improvements in body fat content and lipid profiles in the group continuing an exercise program. Vascular function was significantly better in those children continuing exercise (n=22) compared with children who withdrew from the exercise program (n=19) (P<0.05). CONCLUSIONS: Obesity-related vascular dysfunction in otherwise healthy young children is partially reversible with diet alone or particularly diet combined with exercise training at 6 weeks, with sustained improvements at 1 year in those persisting with diet plus regular exercise.

Adjusting bone mass for differences in projected bone area and other confounding variables: an allometric perspective.

The traditional method of assessing bone mineral density (BMD; given by bone mineral content [BMC] divided by projected bone area [Ap], BMD = BMC/Ap) has come under strong criticism by various authors. Their criticism being that the projected bone "area" (Ap) will systematically underestimate the skeletal bone "volume" of taller subjects. To reduce the confounding effects of bone size, an alternative ratio has been proposed called bone mineral apparent density [BMAD = BMC/(Ap)3/2]. However, bone size is not the only confounding variable associated with BMC. Others include age, sex, body size, and maturation. To assess the dimensional relationship between BMC and projected bone area, independent of other confounding variables, we proposed and fitted a proportional allometric model to the BMC data of the L2-L4 vertebrae from a previously published study. The projected bone area exponents were greater than unity for both boys (1.43) and girls (1.02), but only the boy's fitted exponent was not different from that predicted by geometric similarity (1.5). Based on these exponents, it is not clear whether bone mass acquisition increases in proportion to the projected bone area (Ap) or an estimate of projected bone volume (Ap)3/2. However, by adopting the proposed methods, the analysis will automatically adjust BMC for differences in projected bone size and other confounding variables for the particular population being studied. Hence, the necessity to speculate as to the theoretical value of the exponent of Ap, although interesting, becomes redundant.