Itch in Adult Population with Type 2 Diabetes Mellitus: Clinical Profile, Pathogenesis and Disease-Related Burden in a Cross-Sectional Study

Abstract

Background: Despite growing interest in itch, data regarding itch in type 2 diabetes mellitus (DM2) are still limited, and mostly based on outdated studies. This study aimed to evaluate the clinical characteristics of itch in the adult population with DM2 and explore potential underlying causes. Methods: The study group consisted of 109 adult patients with DM2. Standardized questionnaires were completed in order to assess the itch intensity [Numerical Rating Scale (three days, 24hours) (NRS)] and the Four-item Itch Questionnaire (4IIQ) and to assess the psychological impact of itch [ItchyQoL, Six-Item Stigmatization Scale (6-ISS), Hospital Anxiety and Depression Scale (HADS)]. Skin dryness was evaluated clinically and by non-invasive assessment of epidermis moisturizing. Neuropathy was assessed using the clinical Katzenwadel neuropathy scale. Results: Itch occurred in 35.8% of adult patients with DM2, with NRSmax three days 6.31 ± 2.16 and 8.1 ± 3.5 points in 4IIQ. Itchy patients have had significantly higher FPG levels compared with the non-itchy population (p = 0.01). Patients with itch had a significantly higher possibility of neuropathy compared with non-itchy subjects (p < 0.01). Skin xerosis was significantly more advanced in patients with itch compared to those without (p < 0.01). The mean ItchyQol score was assessed as 41.2 ± 13.4 points, indicating mild life quality impairment and correlated positively with itch intensity. Itchy subjects had significantly higher scores in both anxiety and depression dimensions of HADS (in each p < 0.01). Conclusions: We suggest that the primary cause of itch is prolonged poor diabetes control with altered glucose and insulin levels, subsequently causing skin dryness and neuropathy in long-lasting DM2.

Psychosocial Burden of Itch among Renal Transplant Recipients

“…The differences might be attributed to the higher general prevalence of psychiatric comorbidities in patients after KTx. In our study 34.4% of non-itchy RTRs suffered from depression and 33.3% from anxiety, while in the study by Stefaniak et al [ 46 ] only 1.4 and 5.7% had these, respectively. It is important to underline that RTRs may suffer from an important psychological strain due to multiple comorbidities (including DM2), polypharmacy, and uncertainty about their future health [ 8 ].…”

“…Although QoL assessment in both itchy RTR and DM2 groups was similar (ItchyQoL mean score of 41.76 ± 16.05 points and 41.2 ± 13.4 points, respectively), the prevalence of depression and anxiety were significantly higher in our study. In comparison, depression, and anxiety among itchy DM2 patients were assessed as comprising 33.3 and 7.6% of patients, respectively [ 46 ], while in our study there were 65.6% itchy RTR with depression and 53.7% with anxiety. The differences might be attributed to the higher general prevalence of psychiatric comorbidities in patients after KTx.…”

“…Interestingly, itch in RTR seems to have higher influence on mental status than in other systemic diseases e.g., diabetes mellitus Type 2 (DM2). In the study performed by Stefaniak et al [ 46 ] authors assessed the impairment of QoL, as well as prevalence of anxiety and depression among itchy patients with DM2. Although QoL assessment in both itchy RTR and DM2 groups was similar (ItchyQoL mean score of 41.76 ± 16.05 points and 41.2 ± 13.4 points, respectively), the prevalence of depression and anxiety were significantly higher in our study.…”

Neuroinflammation Involved in Diabetes-Related Pain and Itch

“…An intense scratching habit lasting more than 6 weeks is classified as chronic itching ( Cevikbas and Lerner, 2020 ). The prevalence of chronic itching in the general population is ∼22% ( Weisshaar, 2016 ), and the prevalence in DM is quite various, ranging from 18.4 to 35.8% ( Neilly et al, 1986 ; Ko et al, 2013 ; Stefaniak et al, 2021a ; Stefaniak et al, 2021b ). This huge difference can be attributable to inconsistent definitions, varied tools for itch evaluation, age, gender, and diabetic populations with different diabetes types.…”

“…Over the past decade, extensive research has been conducted on the mechanisms of itch, including peripheral and central neural mechanisms such as receptors and pathways involved in itch perception ( Dong and Dong, 2018 ). According to the researchers, there are two main causes of the itch in diabetics, containing skin xerosis and diabetic polyneuropathy, suggesting that itch originates from dermatology or neurology ( Stefaniak et al, 2021b ). Additionally, oxidative stress and nerve inflammation contribute to diabetic polyneuropathy ( Hagen and Ousman, 2021 ).…”