Thyroid function in hidradenitis suppurativa: a population-based cross-sectional study from Denmark.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease. Numerous studies have associated HS with obesity, and recently with metabolic syndrome (MetS). Both obesity and MetS are linked with metabolic changes. Thyroid hormones play a central role in metabolism and exert pleiotropic effects on adipogenesis and the basal metabolism of lipids and glucose. We hypothesized that patients with HS have an altered or dysfunctional metabolism expressed as thyroid function. AIM: To investigate thyroid function in individuals with HS compared with healthy controls (HCs). METHODS: We conducted a retrospective comparative cross-sectional study using blood samples and questionnaire-based self-reported information to assess thyroid function. RESULTS: Our study comprised 430 patients in a population-based HS group, and 20 780 HCs. The age/sex-adjusted analysis showed a significantly lower level (P < 0.001) of thyroid-stimulating hormone (TSH) and a significantly higher level (P < 0.0001) of total triiodothyronine (tT3) for the HS compared with the HC group. The age/sex-adjusted analysis also showed a significant association between clinical hyperthyroidism and HS (an OR = 1.91, 95% CI 1.19-3.07; P = 0.02). When this analysis was adjusted further for the potential confounders of body mass index, smoking and oral contraception, the results remained significant. CONCLUSION: This study suggests that HS is associated with hyperthyroidism. Hyperthyroidism may indicate an altered or dysfunctional metabolism.

Is hidradenitis suppurativa associated with anaemia?: a population-based and hospital-based cross-sectional study from Denmark.

BACKGROUND: Chronic inflammatory diseases may be associated with anaemia of inflammation. Hidradenitis suppurativa is a chronic inflammatory dermatological disease associated with metabolic comorbidities, low quality of life and fatigue. Anaemia may cause fatigue, and it has been hypothesized that HS-related fatigue may be partly due to anaemia. OBJECTIVE: Our objective was to investigate a possible association between HS and anaemia. METHODS: We performed a hospital-based and population-based cross-sectional study investigating the red blood cell profile, i.e. haemoglobin. RESULTS: We identified a total of 32 hospital HS individuals, 430 population HS individuals and 20,780 population non-HS control individuals. The age-sex-smoking-adjusted analyses showed no differences in the haemoglobin level of the HS groups vs. the control group. Analyses of the anaemic subgroup of HS individuals revealed that 60% had normocytic anaemia and 40% microcytic anaemia, in concordance with anaemia of inflammation. CONCLUSION: In contrast to our hypothesis, this study showed that HS is not associated with anaemia. Thus, anaemia may not be the cause of the described fatigue in HS patients. Furthermore, the results indicate that if an HS patient does suffer from anaemia it is most likely to be normocytic or microcytic and thus compatible with anaemia seen in other chronic inflammatory disorders.

Body composition and basal metabolic rate in Hidradenitis Suppurativa: a Danish population-based and hospital-based cross-sectional study.

BACKGROUND: Several studies have suggested an association between Hidradenitis Suppurativa (HS) and obesity. Obesity is often expressed as Body Mass Index (BMI). However, BMI lacks information on body composition. General obesity is a predictor of health status and cardiovascular risk, but body composition (e.g. abdominal fat) may be more so. Basal metabolic rate (BMR) is an expression of resting metabolism and may serve as a complementary tool when assessing the possibly underlying metabolism behind a persons' body composition. OBJECTIVE: To investigate the body composition and basal metabolic rate in individuals with HS compared with healthy controls. METHODS: We performed a cross-sectional study on both a hospital-based and population-based HS group and compared with controls using Bioelectrical Impedance Analysis to assess body composition. RESULTS: We identified a hospital-based HS group of 32 hospital HS patients, a population-based HS group of 430 population HS patients, and 20 780 controls. Age- and sex-adjusted analyses showed a 10.12% (P < 0.0001) significantly higher fat percentage in the hospital-based HS group and 3.11% (P < 0.0001) significantly higher fat percentage for the population-based HS group compared to controls. Correspondingly, the HS groups had a lower muscle percentage (P < 0.0001) and lower bone mass percentage (P < 0.0001). Furthermore, visceral fat rating (P < 0.0001), Body Mass Index (P < 0.0001), waist circumference (P < 0.0001), and Waist/Hip Ratio (P < 0.0001) was significantly higher in HS patients compared with controls. Additionally, age and sex-adjusted analyses showed a higher predicted estimate of BMR for the HS groups compared with controls (154.56 kcal/day (95% CI 54.96-254.16) (P = 0.0031) for the hospital-based HS group, and 82.63 kcal/day (95%CI 59.70-105.56) (P < 0.0001) for the population-based HS group). CONCLUSION: Hidradenitis Suppurativa is associated with a high fat percentage, high visceral fat, and low muscle percentage adding to the morbidity of HS. The higher predicted estimate of basal metabolic rate (BMR) in HS patients may reflect a dysfunctional metabolism contributing to the high-fat-body composition.