Voice changes may help ID high blood sugar levels in CFRD: Study

Human voice may be tool in future to assess CF-related diabetes

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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Changes in two human voice parameters may help identify poor control of blood sugar levels in people with cystic fibrosis (CF) who have CF-related diabetes (CFRD), a pilot study reported.

Lower measures on these parameters, known as fundamental frequency variation and noise-to-harmonic ratio, were linked with higher glucose, or blood sugar levels in patients.

According to the researchers, “the human voice has potential as a non-invasive tool for measuring glucose [sugar] levels and glycemic control status in CFRD patients in the future.”

“Developing this new voice technology may improve screening” for CF-related diabetes, the team wrote, adding, “Voice analysis may be a convenient method for diagnosing and monitoring CFRD.”

The study, “Predicting glycemic control status and high blood glucose levels through voice characteristic analysis in patients with cystic fibrosis-related diabetes (CFRD),” was published in the journal Scientific Reports.

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Cystic fibrosis-related diabetes — known as CFRD and marked by high blood sugar levels — is a common complication of CF, occurring in about 50% of adults with the genetic disorder.

The condition arises as a result of the thick, sticky mucus that accumulates in the pancreas of CF patients, causing impairments in insulin production. Insulin is the hormone that helps clear glucose from the bloodstream.

Early diagnosis and effective monitoring of blood glucose levels is crucial for the management of CFRD. In the U.S., 75% of CF youth and adults with resulting diabetes are reported to use continuous glucose monitoring devices — typically placed on the belly or arm.

But costs, difficulties in monitoring, and issues with insurance coverage constitute frequent barriers to the routine use of such devices.

In this study, researchers noted that changes in blood glucose levels could be linked with alterations in the elasticity of the tissues that compose the larynx, or voice box. That suggests that analyzing patient voices may be a non-invasive and relatively easy way to diagnose and monitor CFRD.

However, how high blood glucose levels may affect the voice characteristics of patients with CFRD remains poorly understood.

To answer this and determine whether voice analysis could help predict high blood sugar levels in CFRD patients, researchers in the U.S. and Thailand conducted a prospective analysis of 43 individuals with the disorder who were treated between March and December 2021.  All were recruited at the Adult CF Center at the Emory University School of Medicine, in Atlanta, in the U.S.

Among the patients, 18 had higher than normal levels of a measure of blood sugar called HbA1c. Specifically, their HbA1c levels were at or higher than 7%.

The remaining 25 individuals had levels within the normal range. HbA1c levels reflect the amount of blood sugar (glucose) attached to hemoglobin, the protein that carries oxygen in red blood cells.

Using point-of-care blood glucose testing, or POCT, the team found that mean glucose levels in the blood were 183 mg/dL in the group with HbA1c of at least 7%, and 123 mg/dL in patients with lower HbA1c. In this study, POCT was done with the OneTouch Verio Flex glucose meter.

Voice samples of a sustained “a” vowel were recorded for each participant, and voice characteristics were analyzed using the Computerized Speech Lab with the Multi-Dimensional Voice Program.

The analysis revealed that CFRD women with HbA1c levels of 7% or higher exhibited a significantly lower noise-to-harmonic ratio, or NHR — a measure of speech quality — than women with lower HbA1c.

In these patients, for every 1% increase in HbA1c, NHR decreased 0.0058. In contrast, no difference was seen in men with CFRD.

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Human voice measure called vF0 impacted in both men and women

The researchers then compared patients with glucose levels of 200 mg/dL or higher versus those with lower glucose levels. In both men and women, another voice measure called fundamental frequency variation, or vF0, was lower in individuals with 200 mg/dL glucose or higher.

Further analysis showed that a 1% decrease in vF0 was associated with a 1.2% increase in the risk of having glucose levels at or higher than 200 mg/d, as measured using POCT.

Also, CFRD for one year was linked to a significantly higher risk — 19.12% — of high glucose in POCT.

We found differences in voice parameters that distinguished normal glycemic [sugar level] control from inadequate and poorly controlled CFRD in patients with CF.

Overall, these parameters were deemed to be useful for identifying individuals with higher blood sugar.

“We found differences in voice parameters that distinguished normal glycemic [sugar level] control from inadequate and poorly controlled CFRD in patients with CF,” the researchers wrote.

More research now is needed on this potential diagnostic and monitoring tool, the team said.

“Larger sample sizes examining voice characteristics and laryngeal imaging techniques are warranted to further investigate the feasibility of using voice as a biomarker for glycemic control in CFRD,” the study concluded.