A cross-sectional, observational, case-control study was performed in our Medical Center. A medical record comprised of 4150 female patients with LUTs resulting from female urinary diseases between December 2017 and December 2019 were reviewed in our institute. Disease distribution of this cohort was as follows: UI (15.03%), frequent urination (58.18%), pelvic organ prolapse(POP) (11.76%), neurogenic bladder (1.79%), urethral diverticulum (0.36%), fistula (0.85%), pelvic or urethral mass (0.31%), IC/BPS (2.62%), female bladder outlet obstruction(FBOO) (0.34%), urinary tract infection(UTI) (2.52%) and Others (6.23%) (Fig 1).
The diagnosis of IC/BPS is made by the same senior urologist in our medical center based on the National Institute of Diabetes, Digestive and Kidney Diseases guidelines[1]. Among them, patients over 18 years old who underwent hydrodistension and biopsy in our institute were included in the case group.
As for control group, female patients with transient LUTs, but without 1) urological cancers, stones, UTI, UI, OAB, POP, neurogenic bladder, urethral diverticulum, FBOO, IC/BPS, fistula and pelvic or urethral mass; 2) without liver and thyroid diseases; 3) without chronic obstructive pulmonary disease, were included. However, people with following conditions should be excluded: 1) evidence of thyroid, kidney or liver diseases, as established by medical records; 2) use of corticosteroids or medications that might interfere with glucose homeostasis except oral hypoglycemic agents; 3) unavailable or incomplete medical records; 4) Being loath to perform a follow-up; 5) less than 18 years old or a concomitant of geneogenous female urinary disease.
After obtained an approval from the ethics committee in our Medical Center for this study, patients were contacted and subsequently volunteered to undergo a follow-up.
The first objective of this study was to compare the incidence of MetS in patients with and without IC/BPS. As secondary objectives, the number of voids per day, the number of night urination, O’Leary-Sant Interstitial Cystitis Symptom index (ICSI), O’Leary-Sant Interstitial Cystitis Problem Index (ICPI), and 10-point visual analogue scale (VAS) in two groups were evaluated.
The MetS diagnosis requires finding three or more of the following components according to American Heart Association/National Heart, Lung, and Blood Institute, and International Diabetes Federation interim consensus statement[2]:
a. obesity (defined as body mass index [BMI] ≥ 28 kg/m2);
b. high blood pressure (defined as systolic ≥ 130 and/or diastolic ≥ 85 mm Hg, or antihypertensive drug treatment);
c. elevated fasting glucose (≥ 5.6 mmol/l, or type 2 diabetes mellitus, or drug treatment for hyperglycemia);
d. low high-density lipoprotein-cholesterol (defined as < 1.3 mmol/l in females or drug treatment for this abnormality);
e. hypertriglyceridemia (defined as ≥ 1.7 mmol/l or treatment for this abnormality).
Notably, waist circumferences were not routinely measured in our institute; therefore, we selected BMI (calculated by weight/height2) as the substitution. Obesity was defined as BMI ≥ 28 kg/m2 in the Chinese population[3].