Screening of Serum Alkaline Phosphatase and Phosphate Helps Early Detection of Metabolic Bone Disease in Extremely Low Birth Weight Infants

Abstract

Background: Extremely low birth weight (ELBW, <1,000 g) infants have a high risk of metabolic bone disease (MBD). Because of the late appearance of radiological signs, diagnosis of MBD in ELBW infants might be delayed, and its prevalence underestimated in this group of patients. This study adopted serial screening of serum alkaline phosphatase (ALP) and phosphate (P) of ELBW infants to determine whether such screening is helpful for the early detection of MBD.Materials and Methods: We performed a retrospective study of preterm infants with a gestational age ≤ 31 weeks and birth weight <1,000 g. MBD was absent (ALP ≤500 IU/L), mild (ALP >500 IU/L, P ≥4.5 mg/dL), and severe (ALP >500 IU/L, P <4.5 mg/dL); MBD was divided into early MBD (≤4 weeks after birth) and late MBD (>4 weeks after birth) according to the time of onset.Results: A total of 142 ELBW infants were included, with a median gestational age of 28.1 (26.5–29.7) weeks and a median birth weight of 875 (818–950) g. Seventy-three cases of MBD were diagnosed, and the total prevalence was 51.4% (mild MBD, 10.6%; and severe MBD, 40.8%). Male sex, breastfeeding, and sepsis would increase the risk of severe MBD. Most MBD in ELBW infants occurred at 3–4 weeks after birth. Sixty-two percent (45/73) of infants were diagnosed as having early MBD, which are diagnosed earlier than late MBD [24 (21–26) vs. 39 (36–41), t = −7.161; P < 0.001]. Male sex [odds ratio (OR), 2.86; 95% confidence interval (CI), 1.07–7.64; P = 0.036], initial high ALP levels (OR, 1.02; 95% CI, 1.01–1.03; P < 0.001), and breastfeeding (OR, 5.97; 95% CI, 1.01–25.12; P = 0.049) are independent risk factors for the development of early MBD.Conclusion: The risk of MBD among ELBW infants is very high. Most cases occurred early and were severe. Male sex, initial high ALP levels, and breastfeeding are closely related to the increased risk of early MBD. Serial screening of serum ALP and P helps early detection of MBD; it is recommended to start biochemical screening for ELBW infants 2 weeks after birth and monitor their biochemical markers weekly.

Hydroxy-Safflower Yellow A Alleviates Osteoporosis in Ovariectomized Rat Model by Inhibiting Carbonic Anhydrase 2 Activity

“…In Stephen's study (Coburn et al, 1998), inorganic phosphates act as competitive alkaline phosphatase inhibitors to inhibit serum ALP activity. Moreover, hypophosphatemia and elevated serum ALP levels were likely to lead to decreased bone mineral content and trabecular bone number (Zhang et al, 2021). The results showed that the level of ALP in the model group was higher than that in the control group, and the content of serum inorganic phosphorus was decreased, indicating that it accelerated the bone tissue and bone transformation.…”

Relationship of caffeine regimen with osteopenia of prematurity in preterm neonates: a cohort retrospective study

“…In this retrospective study, the serum-ALP concentration at the 4 th week of life was used as a surrogate marker for the risk of developing OOP in preterm neonates as radiographic studies were not performed on all neonates till the 4 th week of life for evaluating the risk of osteopenia [20,21,23]. Reported cutoff values of serum-ALP concentration of 500 IU/L were used, at which osteopenia is detected with 100% sensitivity and 80.77% specificity [21].…”

“…The serum-P levels were recorded for all the patients. Neonates with serum-P levels lower than 5.6 mg/dL (< 1.8 mmol/L) are reported to have a greater risk for MBD and development of OOP with diagnostic sensitivity and specificity of 70% and 100%, respectively [20].…”

“…In the clinical setting, serum-alkaline phosphatase (Serum-ALP), serum phosphorous (Serum-P), and serum-Ca have been commonly used for MBD screening in preterm neonates due to their simplicity and ease of measurement [20,21]. Because elevation in Serum-ALP mostly precedes radiological changes and prompts an additional screening for the confirmation of the diagnosis of OOP.…”

“…However, the detection of early-onset and mild to moderate forms of MBD may not possible through radiological screening as radiographical changes are not evident until bone mineralization is decreased by ≥ 20% [18]. Serum-ALP > 500 units/L has a sensitivity of 100% and specificity of 81% to detect radiologic OOP [20]. In addition, serum-P levels < 5.6 mg/dL (< 1.8 mmol/L) are reported to have a greater risk for MBD and development of OOP with diagnostic sensitivity and specificity of 70% and 100%, respectively [22].…”