Gender Differences in Hypoglycaemia Among Type 1 and Insulin-Treated Type 2 Diabetes: Insights from the Hypo-METRICS Study

Highlight

• Women with both type 1 and insulin-treated type 2 diabetes report more symptomatic hypoglycaemia episodes despite similar exposure to low glucose levels.
• Symptom patterns differ by gender; women with type 1 diabetes exhibit a broader range of autonomic and neuroglycopenic symptoms compared to men.
• Continuous glucose monitoring (CGM) data reveal no gender differences in time spent below the hypoglycaemic threshold, highlighting subjective symptom discrepancies.
• Findings suggest inherent gender-based differences in hypoglycaemia perception or reporting, warranting tailored clinical assessment and future research.

Study Background

Hypoglycaemia remains a critical challenge in diabetes management, especially for individuals on insulin therapy. It can result in numerous acute adverse events, ranging from neuroglycopenic symptoms like confusion to autonomic manifestations such as sweating and palpitations, jeopardizing patient safety and quality of life. Evidence suggests gender may influence hypoglycaemia risk and symptom perception, but existing data are limited and often derived from artificial clinical settings. Clarifying gender differences in hypoglycaemia expression and frequency is pivotal for optimizing personalized diabetes care and informing clinical guidelines.

Study Design

The Hypo-METRICS study is a prospective, 10-week, observational investigation conducted in free-living environments to examine hypoglycaemia experience in adults with type 1 diabetes (n=274) and insulin-treated type 2 diabetes (n=321). Participants wore blinded continuous glucose monitoring devices to record glucose patterns objectively. Concurrently, they logged hypoglycaemia symptoms in real time via a specially developed smartphone application.

Hypoglycaemia was defined through two criteria: either a sensor glucose measurement below 4 mmol/L or any symptomatic episode promptly relieved by carbohydrate intake. Symptoms were categorized as autonomic (hunger, sweating, shaking, palpitations) or neuroglycopenic (confusion, speech difficulty, coordination issues, headache).

Gender differences were examined using appropriate statistical tests including chi-square, Fisher’s exact test, and Wilcoxon rank-sum test to compare symptom frequency, combinations, and quantitative CGM metrics.

Key Findings

The study cohorts differed in gender composition and CGM routine use: the type 1 diabetes group included 54% women, with 76% regularly using CGM, while the type 2 diabetes group was 63% male and 41% CGM users.

Despite no significant gender differences in objective time spent in hypoglycaemia across cohorts (p>0.05), symptomatic hypoglycaemia reporting markedly differed. Women with type 1 diabetes reported an average of 4.3 episodes per week compared to 3.3 in men (p=0.003), while those with type 2 diabetes reported 1.4 versus 1.0 episodes weekly in men (p=0.006).

In type 1 diabetes, women documented a wider variety of combined autonomic and neuroglycopenic symptoms. Notably, confusion alone was a relatively rare sole symptom, observed in 0.9% of episodes in women and 2.3% in men. For type 2 diabetes, symptom patterns showed more combination types across genders; confusion alone was reported in 0.3% of male episodes and not seen in female episodes.

These findings underline a gender disparity in the subjective hypoglycaemia experience, even under similar biochemical exposures measured by CGM.

Expert Commentary

The Hypo-METRICS study robustly delineates gender differences in hypoglycaemia symptoms using a novel, real-time data collection method alongside objective glucose measurement. The absence of time-in-hypoglycaemia differences paired with substantial symptom reporting disparity suggests potential gender variations in hypoglycaemia awareness, symptom perception, or reporting behavior. This aligns with previous hypotheses that women may experience or report symptoms more intensely or frequently.

Limitations include potential selection bias towards motivated participants familiar with CGM technology, which may not fully reflect broader populations. Furthermore, psychosocial factors, hormonal influences, and differences in hypoglycaemia counterregulation were not explored and warrant further mechanistic investigation.

Clinicians should consider these gender-specific symptom profiles when assessing hypoglycaemia risk and tailoring education and management strategies. Future clinical guidelines could integrate these insights to improve hypoglycaemia detection and prevention across genders.

Conclusion

The Hypo-METRICS study elucidates that despite equivalent biochemical hypoglycaemia exposure, women with type 1 and insulin-treated type 2 diabetes report more frequent and diverse symptomatic episodes than men. These findings highlight the need for gender-sensitive approaches in diabetes management to enhance hypoglycaemia recognition and treatment. Further research is essential to uncover biological and psychosocial underpinnings of these differences and translate them into effective clinical interventions.

Funding and Registration

Supported by the Hypo-RESOLVE Consortium, details of funding and study registration can be found alongside the publication at https://pubmed.ncbi.nlm.nih.gov/42322375/.