Neuropeptides in Newborn Blood May Help Objectively Measure Pain in Babies Who Can't Speak | Research

The takeaway

Substance P, neurokinin A, neuropeptide Y, and cortisol levels in newborn blood correlated with pain scale scores, suggesting peptide biomarkers could help objectively measure neonatal pain.

p = 0.02 for NPY change
Neuropeptide Y levels significantly decreased in response to painful procedures in full-term newborns

What the researchers found

Significant decreases in neuropeptide Y (p = 0.02) and neurokinin A (p = 0.03) were observed.

Why it matters

Understanding neonatal pain is crucial for improving care in newborns. Identifying reliable biomarkers can lead to better pain management strategies.

How the study worked

The study involved 54 full-term neonates and measured biomarker levels alongside two pain assessment scales.

What this study cannot tell us

The study's sample size was limited to 54 neonates, which may affect the generalizability of the findings.

How to read the evidence

This is a prospective observational study with a modest sample of 54 neonates. While the correlations are statistically significant, the small sample size limits generalizability. The prospective design strengthens the findings compared to retrospective approaches.

When this study was published

Published in 2023, this study represents current research into peptide biomarkers for neonatal pain. The field is still early-stage, and larger validation studies are needed before clinical implementation.

The bigger picture

Pain assessment in newborns is one of the most challenging problems in pediatric medicine. Current tools rely on behavioral observations — facial expressions, crying, body movement — which are subjective and can miss pain in sedated or neurologically impaired infants. Peptide biomarkers like substance P and neuropeptide Y offer the possibility of objective, measurable pain indicators. This connects to the broader field of neuropeptide research showing how the brain's pain signaling molecules can be detected in blood.

Questions still open

Could a combined peptide biomarker panel plus pain scale score provide more accurate pain assessment than either approach alone?
Why do male newborns show stronger biomarker-pain correlations, and does this reflect biological sex differences in pain processing?
Would these peptide biomarkers be useful in premature infants or those receiving sedation, where behavioral pain scales are less reliable?

Common questions

Why is measuring pain in newborns so difficult?

Babies can't verbally report pain, so doctors rely on behavioral signs like crying, facial grimacing, and body movements. These are subjective and can be influenced by many factors. Sedated, premature, or neurologically impaired infants may show few behavioral signs even when experiencing significant pain.

What do substance P and neuropeptide Y have to do with pain?

Substance P is a neuropeptide that transmits pain signals in the nervous system — it's one of the main chemical messengers that tell your brain something hurts. Neuropeptide Y is involved in stress response and pain modulation. Changes in their blood levels reflect what's happening in the pain signaling system.

Read the original research

The Role of Substance P, Neurokinin A, Neuropeptide Y, and Cortisol in Assessing Neonatal Pain.

Neonatal network : NN, 42(2), 65-71

View on PubMed ↗Publisher’s paper ↗

Citation

Dionysakopoulou, Christina; Lianou, Loukia; Boutopoulou, Barbara; Giannakopoulou, Margarita; Vlachioti, Efrosini; Koumpagioti, Despoina; Bozas, Evangelos; Matziou, Vasiliki. (2023). The Role of Substance P, Neurokinin A, Neuropeptide Y, and Cortisol in Assessing Neonatal Pain.. Neonatal network : NN, 42(2), 65-71. https://doi.org/10.1891/NN.2022-0006