Anecdotal evidence suggests that high pitched voice may be a clinical symptom of hypoglycemia. We conducted a pioneer study aiming at assessing voice variables during hypoglycemia and hyperglycemia. We recruited 10 non-smoking individuals with type 1 diabetes (4 women, 6 men; mean [±SD] age 40.2±10.4 years, diabetes duration 21.4±9.9 years, HbA1c 8.0±1.8%) who were using real time continuous glucose monitoring system (rt-CGM, Guardian Connect, Medtronic) for mean 5.2±0.6 days in controlled hospital setting. At regular intervals during normoglycemia and additionally at blood glucose <70 mg/dl or >200 mg/dl each patient was instructed to record with a professional voice recorder (LS-14, Olympus) a standardized sentence and the sound of vowel ‘a’ for 3 seconds. The voice samples (n=177) were analyzed against CGMS data with the DiagnoScope software (DiagNova, Wroclaw, Poland). Number of fundamental PERiods (PER), time of fundamental PERiods (PERTime), fundamental frequency (F0), energy (E), amplitude of fundamental frequency (AF0), indicator of voiced/phonation probability (Voiced), simple voice quality (SimpleQ), relative average perturbation (RAP), shimmer (Shimm), amplitude perturbation quotient (APQ), four formant frequencies (F1-F4), harmonic perturbation quotients (HPQ), residual to harmonic ratio (R2H), unharmonic to harmonic ratios (U2H), subharmonic to harmonic ratio (S2H), noise to harmonics ratio (NHR), 1st to 4th harmonic to all energy ratio (Fx1-Fx4) were analyzed. In women during hypoglycemia E, AF0, Voiced, F1, F4, R2H, Fx3, Fx4, while in hyperglycemia - RAP and F2 were significantly altered when compared to normoglycemia. In men in hypoglycemia the differences were found in PER, PERTime, Voiced, SimpleQ, Shimm, APQ, F2, U2H, S2H, Fx2, NHR, while in hyperglycemia - PERTime, F1, HPQ, U2H, Fx2 (all p<0.05). We report for the first time that hypoglycemia and hyperglycemia modulate human voice. This phenomenon may offer potential for early detection and prevention of hypoglycemia.
L. Czupryniak: None. E. Sielska-Badurek: None. A. Niebisz: None. M. Sobol: None. M. Kmiecik: None. K. Jedra: None. E. Szymanska-Garbacz: None. K. Niemczyk: None.
Polish Ministry of Science and Higher Education