Related Experiment Video
Updated: May 31, 2025

Author Spotlight: Developing a Bedside Protocol for Kidney and Genitourinary Ultrasonography
Published on: June 21, 2024
Increased sagittal abdominal diameter is associated with a higher risk of kidney stones
Wei Song1, Shugen Li2, Guangchun Wang1
1Department of Urology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
Background:
This study investigates the relationship between sagittal abdominal diameter (SAD), a measure of abdominal obesity, and kidney stone disease (KSD) in the U.S. population. Additionally, it explores potential underlying mechanisms and evaluates the clinical utility of a predictive model.
Methods:
Data were collected from 11,671 participants, including 1,136 cases of KSD. Univariate and multivariate logistic regression analyses, dose-response curves, and mediation effect assessments were employed to examine the association between SAD and KSD. A predictive model was developed and validated using calibration curves, receiver operating characteristic (ROC) curves, and clinical decision curves. Additionally, hematological indicators were analyzed to identify potential mediating factors.
Results:
SAD showed a strong and positive association with KSD, even after adjusting for confounders such as gender, age, and education. The predictive model demonstrated moderate accuracy (AUC = 0.661) and clinical utility. Hematological analyses indicated that granulocyte count (GRAN) significantly mediated the relationship between SAD and KSD (P < 0.001).
Conclusions:
SAD is a significant risk factor for KSD, underscoring the role of abdominal obesity in kidney stone formation. The predictive model demonstrates potential clinical applications for early risk assessment and management of KSD.
Related Concept Videos
External Anatomy of the Kidney
The kidneys are located in the retroperitoneal space on either side of the vertebral column, protected posteriorly by the 11th and 12th ribs. The right kidney sits slightly lower than the left owing to the presence of the liver...
Kidney Structure
Internal Anatomy of the Kidney
Anatomical Position and Dimensions
The kidneys are retroperitoneal organs positioned against the posterior abdominal wall on either side of the spine, roughly between the twelfth thoracic and third lumbar vertebrae. Each kidney is typically 10-12 cm long, 5-6 cm wide, and 3-4 cm thick, weighing about 150 grams.
Renal Cortex
The outermost region of the kidney is the...
Abdominal Regions and Quadrants
The simpler quadrants approach, which is more commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersects at the patient's umbilicus (navel). The four...
Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...
Disorders of the Urinary System
Urinary tract infections (UTIs) are one of the most common urinary system disorders. They are caused by bacteria that enter the urethra and can spread to the bladder resulting in cystitis. Pyelonephritis is the result of a UTI that has ascended to the level of the...

