Background

Frozen shoulder (FS) is a common condition and affects how the shoulder moves, making it very stiff and sore. The shoulder joint becomes inflamed and tightened due to scarring in the joint called fibrosis. It can take years to get better, and for around 50% of individuals the symptoms last even longer. FS causes a profound negative impact on physical and mental health, including disturbed sleep, low mood, difficulty performing everyday activities and, in many cases, are unable to continue working. FS affects around 1 in 10 people, and almost twice as many women as men between the ages of 40-60 years, but it is unknown why. It is thought to either be related to changes in sex hormones during the menopause, or due to the way the body handles sugar and fat, which changes with the menopause. However, associations between the menopause transition and FS are not well established and previous evidence has been poor quality. Current treatments include physiotherapy, a steroid injection or surgery but none of these treat the underlying cause of FS. Women with FS said they would like to know why they developed FS and more early treatment options to avoid a long recovery or an operation.

Aim This study aims to understand if there is a link between the menopause, changes in blood sugar levels and FS in women.

Plan In Part 1, women who have had FS will fill in an electronic questionnaire to give us information about their menopause status at the onset of FS, how long their symptoms lasted, what treatments they tried, and if they had any other health conditions. This will enable us to determine the relationship between the menopause and the onset of FS.

In Part 2, the investigators will invite 18 perimenopausal women with recently diagnosed FS and 18 matched women without FS to attend a one-day visit at the University of Nottingham. The investigators will measure their blood sugar levels over two weeks using a small monitor on their arm. The investigators will assess their menopause symptoms and shoulder related outcomes using validated questionnaires. The investigators will assess their shoulder movement and measure body fat and muscle levels, physical activity levels, diet, and take a blood sample to test sex hormones, inflammation and lipids, as well as markers related to frozen shoulder. This will help us to assess the relationship between blood glucose control and the onset of FS in perimenopausal women.

Impact This research will help us understand if there's a link between menopause, blood sugar control, and FS. It could lead to new clinical trials testing treatments early in FS, such as a glucose lowering medication or hormone therapy, to help women recover faster and avoid surgery. This may improve clinical outcomes in women with FS and reduce costs associated with treating FS. This important question came directly from patients and has not been studied in depth before. The investigators plan to share the results widely through health newsletters, podcasts, research conferences, and medical journals.

Part 1

Inclusion criteria:

• Any women > 18 years with a history of frozen shoulder diagnosed by a clinician

Exclusion criteria:

• Any women without a clear previous diagnosis of frozen shoulder

Part 2:

Inclusion criteria:

• Perimenopausal women (self-assessment)
• Aged 40-60 years
• Diagnosed with FS within the last 12 months OR
• Matched controls (women aged 40-60 years without FS).

Exclusion criteria:

• Diabetes mellitus,
• Thyroid dysfunction,
• Secondary FS (e.g. posttraumatic),
• Use of medications influencing hormonal or metabolic parameters (e.g. hormone replacement therapy [HRT].

Part 1: Any woman over 18 years of age with a current or previous history of frozen shoulder

Part 2: Perimenopausal women with recent diagnosis of primary frozen shoulder and matched controls