Gestational Diabetes and Type 1 Diabetes Affects Gustatory Sense but not Saccadic Eye Movements—A Prospective Cohort Study

Background: Nutritional therapy is the basis of diabetes treatment. Non-compliance with dietary recommendations is a common obstacle in the treatment of diabetes, with attenuated taste perception being one of many potential responsible factors. We investigated the impact of gestational diabetes mellitus (GDM) and type 1 diabetes (T1D) on two sensory modalities—saccadic eye movement and gustatory sense. Methods: In this prospective cohort study, we included 91 participants—28 women with GDM, 26 nonpregnant women with T1D and 37 non-diabetic non-pregnant women. We performed gustatory sense examination (GSE) with test strips for taste modalities and saccadic eye movement examination (SEME) and compared obtained results between study groups. This study was started prior to the requirement for registration of interventional cohort studies. Results: The mean age of participants was 29.4 ± 5.2 years. Women from the GDM group were older (31.0 [interquartile ranges (IQR): 29.0–35.8] vs. 28.0 [IQR: 22.5–34.8] and 28.0 [IQR: 25.3–30.0] years, p = 0.003) and had higher pre-pregnancy body mass index (BMI) compared to women with T1D and controls (26.2 [IQR: 20.8–28.5] vs. 22.6 [IQR: 20.9–24.4] and 20.9 [IQR: 19.1–22.3] kg/m2, p = 0.001). The total gustatory score was lower in women with GDM and T1D than controls with no significant difference between the GDM and T1D groups (68.8% [56.3%–75.0%], 67.5% [55.0%–76.3%], and 80.0% [70.0%–85.0%], respectively, p < 0.001). Saccadic latency was borderline higher in GDM than in the control group (189.5 ms [162.8–214.3] vs. 167.5 ms [154.5–186.3], p = 0.054) and duration was shorter in GDM than in T1D group (50.0 ms [47.0–53.0] vs. 54.5 ms [48.0–60.3], p = 0.041), with no differences in saccadic amplitude, mean and peak velocity between the studied groups. Conclusions: The gustatory sense was attenuated to a similar degree in nonpregnant women with T1D and those with GDM, when compared to non-diabetic non-pregnant women. This partially explains the phenomenon of cravings and affects compliance to dietary recommendations. Gustatory testing could be a potential measure to improve the metabolic control of diabetes and reducing the risk of maternal and neonatal complications of pregnancy. More studies in diverse populations of T1D patients are needed to assess the effectiveness of saccadometry in screening for diabetic neuropathy.