Assessment of Blood Glucose Levels in Neonates in the Sick Neonatal Care Unit: A Comparison Between Glucometer and Glucose Oxidase Methods

Kumari M et al | DOI: 10.65188/nurexus.1056

Page 1

Journal of MedVerse Research & Practice

ISSN: 3107-4278

Assessment of Blood Glucose Levels in Neonates in the Sick Neonatal

Care Unit: A Comparison Between Glucometer and Glucose Oxidase

Methods

Dr. M Kumari

, Dr. S Ferdina

Assistant Professor, Professor

Department of Paediatrics, Guntur Medical College, Guntur.

Email ID: kumarim@gmail.com,

Submission Date: 29.11.2025

Accepted Date:17.12.2025

Published Date: 31.12.2025

DOI: 10.65188/nurexus.1056

article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits

unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Abstract

Background: Neonatal hypoglycaemia is a common metabolic abnormality in sick neonates and may lead to

significant neurological complications if undetected. Rapid and accurate blood glucose assessment is essential in

neonatal care units. This study aimed to evaluate the diagnostic accuracy of bedside glucometers compared with the

laboratory glucose oxidase method in detecting hypoglycaemia among neonates.

Methods: A hospital-based diagnostic accuracy study was conducted in the Neonatal Intensive Care Unit of

Guntur Medical College and Hospital, Andhra Pradesh. A total of 150 neonates requiring blood glucose estimation

were enrolled consecutively. Capillary blood samples were analyzed using a bedside glucometer, while venous

samples were processed using the laboratory glucose oxidase method, which served as the reference standard.

Sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of the

glucometer were calculated.

Results: Among the 150 neonates, 28% were hypoglycaemic according to laboratory glucose measurements. The

glucometer identified hypoglycaemia in 30.7% of neonates. Compared with laboratory estimation, the glucometer

demonstrated a sensitivity of 90.5%, specificity of 92.6%, positive predictive value of 82.6%, negative predictive

value of 96.2%, and overall diagnostic accuracy of 92.0%. Mean blood glucose values were slightly lower when

measured by glucometer (52.6 ± 11.4 mg/dL) than laboratory estimation (55.9 ± 10.8 mg/dL).

Conclusion: Bedside glucometers provide rapid and reliable screening for neonatal hypoglycaemia, facilitating

timely clinical intervention in high-dependency care settings. However, laboratory confirmation remains essential

for precise diagnosis, particularly in borderline or critically low glucose values. The combined use of point-of-care

glucometer testing and laboratory methods can enhance early detection and management of hypoglycemia,

potentially improving neonatal outcomes.

Keywords: Neonatal hypoglycemia; Glucometer; Glucose oxidase; Diagnostic accuracy; Sick neonates

Introduction

Neonatal hypoglycaemia is one of the most frequently encountered metabolic abnormalities during the

early neonatal period and continues to be a major concern in neonatal intensive care units and sick

neonatal care units [1]. It results from an imbalance between glucose supply and metabolic demand

during the critical transition from intrauterine to extrauterine life. During fetal development, glucose is

continuously transferred from the mother through the placenta. After birth, this constant supply is

interrupted, and the neonate must rely on endogenous metabolic pathways such as glycogenolysis,

gluconeogenesis, and ketone body production to maintain glucose homeostasis. Immaturity or disruption

of these adaptive mechanisms increases the risk of hypoglycaemia, particularly in vulnerable neonates.

Kumari M et al | DOI: 10.65188/nurexus.1056

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The incidence of neonatal hypoglycaemia varies widely and is influenced by gestational age, birth weight,

perinatal risk factors, and the diagnostic thresholds applied [2,3]. Preterm infants, infants of diabetic

mothers, small for gestational age and large for gestational age neonates, and those with conditions such

as birth asphyxia, sepsis, or respiratory distress are at higher risk. Hypoglycaemia may be transient or

persistent and can present with nonspecific clinical features, including jitteriness, lethargy, poor feeding,

apnoea, seizures, or hypothermia. Early identification is essential, as recurrent or prolonged

hypoglycaemia has been associated with adverse neurodevelopmental outcomes such as cognitive

impairment, motor deficits, and epilepsy [4,5].

Despite its clinical importance, there is no universally accepted definition or single threshold for neonatal

hypoglycaemia. Many professional bodies recommend using operational thresholds based on postnatal

age, clinical status, and risk profile, rather than an absolute glucose cutoff. Current guidelines emphasize

maintaining adequate plasma glucose levels to prevent neurological injury while avoiding unnecessary

interventions, making accurate glucose measurement a central component of neonatal care [6].

Laboratory estimation of blood glucose using enzymatic techniques such as the glucose oxidase method is

considered the reference standard due to its analytical accuracy and specificity [7]. These methods

measure plasma glucose and are relatively unaffected by variations in hematocrit or the presence of

interfering substances. However, laboratory testing may be associated with delays related to sample

transport and processing, which can limit its utility in emergency clinical situations.

Point-of-care testing using bedside glucometers is widely practiced in neonatal units due to rapid

turnaround time and minimal blood volume requirements. However, the accuracy of glucometers in

neonates, especially at low glucose concentrations, remains a concern. Factors such as hematocrit levels,

peripheral perfusion, sample type, device calibration, and operator technique can influence measurements

[8].

Several studies have reported discrepancies between glucometer readings and laboratory glucose values

in neonates, particularly in the hypoglycaemic range, which may lead to misclassification and

inappropriate clinical management [9]. In sick neonatal care units, where rapid decision-making is

critical, evaluating the performance of glucometers against standard laboratory methods is essential to

ensure safe and effective care [10]. The present study aims to estimate blood glucose levels in sick

neonates admitted to the Sick Neonatal Care Unit and to assess the validity of bedside glucometer

measurements by comparing them with the laboratory glucose oxidase method.

Materials and Methods

This hospital-based diagnostic accuracy study was conducted to compare blood glucose measurements

obtained using a bedside glucometer with those measured by the laboratory glucose oxidase method in

sick neonates. The study was carried out in the Neonatal Intensive Care Unit of Guntur Medical College

and Hospital, Andhra Pradesh, which provides intensive care to both inborn and outborn neonates.

Newborns admitted to the NICU who required blood glucose estimation as part of routine clinical

management constituted the study population. A total of 150 neonates were enrolled using consecutive

sampling. Neonates aged 0 to 28 days requiring blood glucose assessment and whose parents or legal

guardians provided written informed consent were included. Infants older than 28 days, neonates with

packed cell volume values below 40 percent or above 65 percent, and those with inadequate or hemolysed

blood samples were excluded due to potential effects on glucometer accuracy.

After obtaining informed consent, blood samples were collected under aseptic conditions. Capillary blood

was obtained by heel prick, and after discarding the first drop, the subsequent sample was analyzed

Kumari M et al | DOI: 10.65188/nurexus.1056

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immediately using a bedside glucometer. The reading displayed by the device was recorded as plasma

equivalent glucose. Simultaneously, approximately 2 mL of venous blood was collected and transported

promptly to the central laboratory for glucose estimation. Laboratory glucose measurement was

performed using the glucose oxidase enzymatic method, which is considered the reference standard.

Samples were processed without delay to minimize pre analytical errors. For diagnostic accuracy

assessment, glucometer results were classified as true positive, true negative, false positive, or false

negative based on comparison with laboratory glucose values.

All data were entered into a structured format and analyzed using the Statistical Package for the Social

Sciences software. Descriptive statistics were used to summarize study variables. Diagnostic performance

parameters including sensitivity, specificity, positive predictive value, and negative predictive value were

calculated, and agreement between the two methods was assessed using appropriate statistical tests, with

laboratory glucose estimation considered the reference standard.

Ethical clearance for the present study was obtained from the Institutional Ethics Committee of Guntur

Medical College, Guntur (Ref No: IEC/GMC-GTR/2023/31874). A detailed Participant Information

Sheet was provided to all participants, and written informed consent was obtained prior to their

enrollment in the study.

Results

Table 1. Baseline characteristics of neonates (n = 150)

Variable

Frequency

Percentage

Male

58.7

Female

41.3

Preterm

42.7

Term

57.3

Low birth weight

48.0

Normal birth weight

52.0

Among the 100 CHB patients, the mean age was 42.6 years, with 61 percent males. Most were HBeAg-

negative (67 percent). Liver enzymes were moderately elevated, and platelet counts were generally

Kumari M et al | DOI: 10.65188/nurexus.1056

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preserved. The APRI and FIB-4 values indicated varying degrees of liver injury. Fibrosis staging showed

that 45 percent had early fibrosis (S0–S1), 24 percent had moderate fibrosis (S2), and 31 percent had

advanced fibrosis (S3–S4).

Table 2. Distribution of blood glucose levels by glucometer and laboratory method

Method

Mean (mg/dL)

Glucometer

52.6

11.4

Laboratory glucose oxidase

55.9

10.8

The mean blood glucose level measured using the bedside glucometer was 52.6 mg/dL with a standard

deviation of 11.4 mg/dL, whereas the mean glucose level estimated by the laboratory glucose oxidase

method was higher at 55.9 mg/dL with a standard deviation of 10.8 mg/dL. This indicates that glucometer

readings tended to be slightly lower than laboratory values, though variability was comparable between

the two methods.

Table 3. Classification of neonates based on glucose status by both methods

Glucose status

Glucometer n (%)

Laboratory n (%)

Hypoglycaemic

46 (30.7)

42 (28.0)

Normoglycaemic

104 (69.3)

108 (72.0)

Total

150 (100)

Based on glucometer measurements, hypoglycaemia was detected in 46 neonates (30.7 percent), while

104 neonates (69.3 percent) were classified as normoglycaemic. Using the laboratory glucose oxidase

method, hypoglycaemia was identified in 42 neonates (28.0 percent), and 108 neonates (72.0 percent)

were found to have normal glucose levels. Overall, the glucometer identified a slightly higher proportion

of hypoglycaemic cases compared to laboratory estimation.

Table 4. Comparison of glucometer readings with the laboratory method

Glucometer / Laboratory

Hypoglycaemia

Present

Hypoglycaemia

Absent

Total

Hypoglycaemia detected

38 (TP)

8 (FP)

Normoglycaemia detected

4 (FN)

100 (TN)

104

Total

108

150

When glucometer readings were compared with laboratory glucose oxidase estimation, 38 neonates were

correctly identified as hypoglycaemic by both methods (true positives), while 100 neonates were correctly

classified as normoglycaemic (true negatives). The glucometer falsely identified hypoglycaemia in 8

neonates who were normoglycaemic by laboratory estimation (false positives) and failed to detect

hypoglycaemia in 4 neonates who were confirmed to be hypoglycaemic by the laboratory method (false

negatives). This comparison demonstrates good overall agreement between the bedside glucometer and

the laboratory glucose oxidase method.

Table 5. Diagnostic performance of a glucometer

Parameter

Value (%)

Sensitivity

90.5

Specificity

92.6

Positive predictive value

82.6

Negative predictive value

96.2

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The bedside glucometer demonstrated high diagnostic performance in detecting neonatal hypoglycaemia.

The sensitivity was 90.5 percent, indicating a strong ability to correctly identify hypoglycaemic neonates.

The specificity was 92.6 percent, reflecting accurate identification of normoglycaemic infants. The

positive predictive value was 82.6 percent, while the negative predictive value was notably high at 96.2

percent, suggesting reliable exclusion of hypoglycaemia.

Discussion

In this diagnostic accuracy study involving 150 sick neonates, bedside glucometer measurements

demonstrated high sensitivity (90.5%) and specificity (92.6%) for detecting neonatal hypoglycaemia,

with an overall diagnostic accuracy of 92.0%. These findings indicate strong agreement between

point-of-care glucometer readings and laboratory glucose oxidase measurements, supporting the utility

of glucometers as effective tools for rapid screening in neonatal care settings.

Our findings are comparable to those reported by Naaz and Gulati, who observed high specificity

(98.2%) and acceptable sensitivity when comparing glucometer measurements with the laboratory

glucose oxidase method in neonates, emphasizing the role of glucometers in early identification of

hypoglycaemia [12]. Similarly, Mehta and Munde demonstrated good correlation between glucometer

and laboratory glucose measurements in high-risk neonates, concluding that glucometers are useful for

bedside screening, particularly in resource-constrained settings [16]. Sreenivasa and Kumar also

reported a strong correlation between glucometer and laboratory values, though they cautioned about

reduced accuracy at very low glucose concentrations [17].

In contrast, Ogunbosi et al. reported lower sensitivity but maintained high specificity for glucometer

measurements, suggesting that some point-of-care devices may underestimate hypoglycaemia,

particularly at critically low glucose levels [13]. Such variability highlights the influence of device

type, calibration standards, sampling techniques, and clinical conditions on glucometer performance.

Older but seminal work by Ho et al. also cautioned against the exclusive reliance on glucometers at

low glucose ranges, recommending laboratory confirmation before definitive clinical decisions are

made [14]. Similar observations were made by Nuntnarumit et al., who reported variability in

glucometer accuracy depending on the device model and glucose range, particularly in neonates with

severe hypoglycaemia [15].

Evidence from systematic reviews and meta-analyses further supports these observations. Richmond

et al. demonstrated that point-of-care glucometers generally exhibit high specificity, while sensitivity

varies depending on device methodology and clinical context, reinforcing the role of glucometers as

screening rather than confirmatory tools [18]. Roth-Kleiner et al. also evaluated multiple point-of-care

devices in neonatal settings and found acceptable agreement with laboratory methods, although

discrepancies were more pronounced at lower glucose concentrations [19]. Pre-analytical and

physiological factors, including hematocrit variation, peripheral perfusion, and operator technique, are

known to affect glucometer accuracy in neonates. Hay highlighted that neonatal glucose metabolism is

highly dynamic, further complicating accurate bedside measurement [20]. Audits conducted in

neonatal intensive care units have shown that strict adherence to sampling protocols, regular

calibration, and quality control measures significantly improve the reliability of glucometer readings

[21].

Conclusion

This study demonstrates that bedside glucometers provide a rapid and reliable method for screening

neonatal hypoglycaemia in sick neonates, showing high sensitivity, specificity, and overall diagnostic

Diagnostic accuracy

92.0

Kumari M et al | DOI: 10.65188/nurexus.1056

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accuracy

when

compared

with

the laboratory

glucose oxidase method.

While glucometers

are

particularly useful for timely detection and clinical decision-making in high-dependency neonatal

units, confirmatory laboratory testing remains essential for precise diagnosis, especially in borderline

or critically low glucose values. Integrating point-of-care glucometer testing with standard laboratory

methods can enhance early identification and management of hypoglycaemia, potentially reducing the

risk of adverse neurodevelopmental outcomes in vulnerable neonates.

Conflict of interest: Nil

Source Of Fund: Nil

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