Growth, bone health, and later outcomes in infants born preterm

Osteopenia of prematurity and associated nutritional factors: case-control study

BACKGROUND

Preterm newborn nutrition affects postnatal skeletal growth and bone mineralization, but studies have not yet fully concluded the relationship between nutrition and osteopenia. This study was intended to investigate the impact of nutritional factors on osteopenia in preterm newborns.

METHODS

This is a case-control study with babies born with gestational age ≤ 32 weeks in a high-risk maternity hospital, between 2018 and 2019. The population consisted of 115 newborns, being 46 cases (40%) and 69 controls (60%). Disease outcome was based on serum alkaline phosphatase levels > 900UL/l and hypophosphatemia < 4 mg/dl. Gestational data at birth and clinical and nutritional follow-up data during 8 weeks postnatally were assessed. Variables were assessed using regressive logistic models.

FINDINGS

Preterm infants who were fed pasteurized fresh human milk with acidity ≥ 4 ºDornic are 5.36 times more likely to develop osteopenia (p = 0.035). Higher calcium intake, compared to controls, also increased the probability of disease occurrence [OR 1.05 (CI 1.006-1.1); p = 0.025], while the presence of a partner [OR 0.10 (CI 0.02-0.59); p = 0.038] and the shortest time using sedatives [OR 0.89 (CI 0.83-0.98); p = 0.010] were protective factors associated with osteopenia. Extremely low birth weight [OR 5.49 (CI 1.20-25.1); p = 0.028], sepsis [OR 5.71 (CI 1.35-24.2); p = 0.018] and invasive ventilatory support [OR 1.09 (CI 1.03-1.18); p = 0.007] were risk factors.

CONCLUSIONS

Acidity and high calcium intake are the main nutritional factors associated with osteopenia of prematurity. Further studies on the use of human milk with lower acidity, recommendation and nutritional supplementation of calcium should be accomplished to guide prevention strategies in newborns at risk for osteopenia during hospital stay.

Sex-Specific Effects of Nutritional Supplements for Infants Born Early or Small: An Individual Participant Data Meta-Analysis (ESSENCE IPD-MA) II: Growth

Neonatal nutritional supplements may improve early growth for infants born small, but effects on long-term growth are unclear and may differ by sex. We assessed the effects of early macronutrient supplements on later growth. We searched databases and clinical trials registers from inception to April 2019. Participant-level data from randomised trials were included if the intention was to increase macronutrient intake to improve growth or development of infants born preterm or small-for-gestational-age. Co-primary outcomes were cognitive impairment and metabolic risk. Supplementation did not alter BMI in childhood (kg/m²: adjusted mean difference (aMD) -0.11[95% CI -0.47, 0.25], p = 0.54; 3 trials, n = 333). Supplementation increased length (cm: aMD 0.37[0.01, 0.72], p = 0.04; 18 trials, n = 2008) and bone mineral content (g: aMD 10.22[0.52, 19.92], p = 0.04; 6 trials, n = 313) in infancy, but not at older ages. There were no differences between supplemented and unsupplemented groups for other outcomes. In subgroup analysis, supplementation increased the height z-score in male toddlers (aMD 0.20[0.02, 0.37], p = 0.03; 10 trials, n = 595) but not in females, and no significant sex interaction was observed (p = 0.21). Macronutrient supplementation for infants born small may not alter BMI in childhood. Supplementation increased growth in infancy, but these effects did not persist in later life. The effects did not differ between boys and girls.

Early Nutrition during Hospitalization in Relation to Bone Health in Preterm Infants at Term Age and Six Months Corrected Age

Aim: to evaluate the potential association of macronutrient intake in the first postnatal weeks on bone mineral content (BMC) and bone mineral density (BMD) in extremely and very preterm infants. Methods: fifty-eight extremely and very preterm infants were included. Daily macronutrient intake was calculated in g kg⁻¹ day⁻¹ from birth up to 36 weeks postmenstrual age. A dual-energy X-ray absorptiometry whole body scan was used to assess BMC and BMD in preterm infants at term corrected age (TCA) and six months corrected age (CA). Results: fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was positively associated with BMC and BMD at TCA. At six months CA, protein and fat intake (g kg⁻¹ day⁻¹) in the first weeks of life were both individual predictors for BMD. Fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was significantly associated with BMC at six months CA. Conclusion: the association of macronutrient intake in the first postnatal weeks on BMC or BMD, at TCA and six months CA, suggest that early nutritional intervention immediately after birth and during early infancy is important for bone health in the first months of life.

Impact of macronutrient supplements on later growth of children born preterm or small for gestational age: A systematic review and meta-analysis of randomised and quasirandomised controlled trials

BACKGROUND

Nutritional supplements may improve short-term growth of infants born small (preterm or small for gestational age), but there are few data on long-term effects and concerns that body composition may be adversely affected. Effects also may differ between girls and boys. Our systematic review and meta-analysis assessed the effects of macronutrient supplements for infants born small on later growth.

METHODS AND FINDINGS

We searched OvidMedline, Embase, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews from inception to January 30, 2020, and controlled-trials.com, clinicaltrials.gov, and anzctr.org.au on January 30, 2020. Randomised or quasirandomised trials were included if the intention was to increase macronutrient intake to improve growth or development of infants born small and growth was assessed after discharge. Primary outcome was body mass index (BMI) in childhood. Data were pooled using random-effect models. Outcomes were evaluated in toddlers (< 3 years), childhood (3 to 8 years), adolescence (9 to 18 years), and adulthood (>18 years). Forty randomised and 2 quasirandomised trials of variable methodological quality with 4,352 infants were included. Supplementation did not alter BMI in childhood (7 trials, 1,136 children; mean difference [MD] -0.10 kg/m2, [95% confidence interval (CI) -0.37 to 0.16], p = 0.45). In toddlers, supplementation increased weight (31 trials, 2,924 toddlers; MD 0.16 kg, [0.01 to 0.30], p = 0.03) and length/height (30 trials, 2,889 toddlers; MD 0.44 cm, [0.10 to 0.77], p = 0.01), but not head circumference (29 trials, 2,797 toddlers; MD 0.15 cm, [-0.03 to 0.33], p = 0.10). In childhood, there were no significant differences between groups in height (7 trials, 1,136 children; MD 0.22 cm, [-0.48 to 0.92], p = 0.54) or lean mass (3 trials, 354 children; MD -0.07 kg, [-0.98 to 0.85], p = 0.88), although supplemented children appeared to have higher fat mass (2 trials, 201 children; MD 0.79 kg, [0.19 to 1.38], p = 0.01). In adolescence, there were no significant differences between groups in BMI (2 trials, 216 adolescents; MD -0.48 kg/m2, [-2.05 to 1.08], p = 0.60), height (2 trials, 216 adolescents; MD -0.55 cm, [-2.95 to 1.86], p = 0.65), or fat mass (2 trials, 216 adolescents; MD -1.3 5 kg, [-5.76 to 3.06], p = 0.55). In adulthood, there also were no significant differences between groups in weight z-score (2 trials, 199 adults; MD -0.11, [-0.72 to 0.50], p = 0.73) and height z-score (2 trials, 199 adults; MD -0.07, [-0.36 to 0.22], p = 0.62). In subgroup analysis, supplementation was associated with increased length/height in toddler boys (2 trials, 173 boys; MD 1.66 cm, [0.75 to 2.58], p = 0.0003), but not girls (2 trials, 159 girls; MD 0.15 cm, [-0.71 to 1.01], p = 0.74). Limitations include considerable unexplained heterogeneity, low to very low quality of evidence, and possible bias due to low or unbalanced followup.

CONCLUSIONS

In this systematic review and meta-analysis, we found no evidence that early macronutrient supplementation for infants born small altered BMI in childhood. Although supplements appeared to increase weight and length in toddlers, effects were inconsistent and unlikely to be clinically significant. Limited data suggested that supplementation increased fat mass in childhood, but these effects did not persist in later life. PROSPERO registration: CRD42019126918.

The Effect of Daily Exercise Program on Bone Mineral Density and Cortisol Level in Preterm Infants with Very Low Birth Weight: A Randomized Controlled Trial

PURPOSE

This randomized controlled double-blinded experimental study was carried out to determine the effects of the daily exercise program on bone mineral density and cortisol level in preterm infants with VLBW matched for birth weight, gestation week, and gender.

DESIGN AND METHODS

The study was carried out with preterm infants (n = 24) hospitalized in the NICU of a tertiary hospital. Ethical committee approval, institutional permission, parental written consent were obtained. A daily exercise program was implemented in preterm infants in the exercise group for 30 days, once a day, and continuing for 7-10 min. Before and after the study the following were evaluated in preterm infants in the exercise and control group: anthropometric measurements, tibia speed of sound (SOS) for bone mineral density, serum cortisol levels.

RESULTS

Serum cortisol levels (p = 0.05) were decreased, bone SOS values in the exercise group were increased (p = 0.009), after the study. The difference between pre-, post-study bone SOS and serum cortisol values of infants in the exercise group were high (p > 0.05). Percentage increases in anthropometric values in the exercise group were higher than the control group after the study (for all; p > 0.05).

CONCLUSIONS

The daily exercise program has positive effect on bone SOS and serum cortisol values in preterm infants. Neonatal nurses can implement the daily exercise program in clinical practice. Trial registration numberClinicaltrials.govNCT03773679.

The long-term impact of very preterm birth on adult bone mineral density

Introduction

Preterm infants are at increased risk of osteopenia of prematurity due to insufficient bone mineral accretion. Data on long term effects of prematurity on bone health are conflicting. This study aimed to compare bone mineral density (BMD) in young adults born very preterm and full-term controls and to examine factors associated with long-term bone health.

Methods

This observational cross-sectional study enrolled 101 young adults (18–29 years) born <29 weeks of gestation and 95 sex- and age-matched full-term controls. Participants underwent dual-energy X-ray absorptiometry to measure areal BMD and body composition. Generalized estimated equations were used to compare groups adjusting for height Z-score, lean body mass and fat mass.

Results

Adults born preterm were shorter and lighter than full-term controls. Areal BMD was reduced at the lumbar spine, the femoral neck and whole body in the preterm versus full-term group, but after adjustment, areal BMD Z-score was only significantly lower at the femoral neck by −0.3 unit (95% confidence interval −0.6 to −0.0). Low BMD (Z-score ≤ −1 standard deviation) at any site was observed in 53% of adults born preterm versus 28% of full-term controls, but this was not statistically significantly different. We did not identify any neonatal factors associated with lower BMD within the preterm group.

Conclusions

Very preterm birth is associated with lower areal BMD at the femoral neck in young adulthood, even after accounting for body size. Whether this will translate into higher risk of osteoporotic fractures later in life remains unknown.

Caffeine is a risk factor for osteopenia of prematurity in preterm infants: a cohort study

Background

Caffeine, the most commonly used medication in Neonatal Intensive Care Units, has calciuric and osteoclastogenic effects.

Methods

To examine the association between the cumulative dose and duration of therapy of caffeine and osteopenia of prematurity, a retrospective cohort study was conducted including premature infants less than 31 weeks and birth weight less than 1500 g. Osteopenia of prematurity was evaluated using chest X-rays on a biweekly basis over 12 weeks of hospitalization.

Results

The cohort included 109 infants. 51% had osteopenia of prematurity and 8% had spontaneous rib fractures. Using the generalized linear mixed model, caffeine dose and duration of caffeine therapy showed a strong association with osteopenia of prematurity. Steroids and vitamin D were also significantly correlated with osteopenia of prematurity while diuretic use did not show a statistically significant effect.

Conclusion

The cumulative dose and duration of therapy of caffeine, as well as steroid are associated with osteopenia of prematurity in this cohort. Future studies are needed to confirm these findings and determine the lowest dose of caffeine needed to treat effectively apnea of prematurity.