Which condition can cause coronary artery disease (CAD)?

Choice A reason: Pyelonephritis, a bacterial kidney infection, causes intrarenal AKI by directly damaging renal parenchyma through inflammation and tubular injury. The infection disrupts nephron function, reducing filtration and leading to acute kidney injury, making this a correct cause of intrarenal damage.

Choice B reason: Nephrotoxins, such as certain drugs or chemicals, cause intrarenal AKI by directly injuring tubular epithelial cells. This disrupts renal filtration and reabsorption, leading to acute kidney injury through toxic cellular damage, making this a correct cause of intrarenal AKI.

Choice C reason: A bladder tumor causes postrenal AKI by obstructing urine outflow, leading to backpressure on the kidneys. It does not directly damage renal parenchyma, as intrarenal AKI requires, making this choice incorrect for intrarenal causes of kidney injury.

Choice D reason: Dehydration causes prerenal AKI by reducing blood volume and renal perfusion, not directly damaging the renal parenchyma. Intrarenal AKI involves intrinsic kidney damage, so dehydration’s hypoperfusion effect makes this choice incorrect for intrarenal AKI.

Choice E reason: Ureteral obstruction causes postrenal AKI by blocking urine flow, increasing pressure on the kidneys. It does not involve direct parenchymal damage, as required for intrarenal AKI, making this choice incorrect for the specified type of kidney injury.

Choice A reason: Osteoporosis results from an imbalance where osteoclast-mediated bone resorption outpaces osteoblast-mediated bone formation, reducing bone density and strength. This leads to fragile, porous bones prone to fractures, especially in the elderly, due to hormonal changes or reduced calcium absorption, making this the correct description.

Choice B reason: An abnormal immune response causing synovitis and cartilage deterioration describes rheumatoid arthritis, not osteoporosis. Rheumatoid arthritis involves autoimmune inflammation of joints, not bone density loss. Osteoporosis primarily affects bone matrix, not cartilage or synovial tissues, making this choice incorrect.

Choice C reason: Cartilage erosion from mechanical stress describes osteoarthritis, a degenerative joint disease, not osteoporosis. Osteoporosis affects bone density, not articular cartilage. Mechanical stress may exacerbate joint issues but does not cause the systemic bone loss characteristic of osteoporosis, making this choice incorrect.

Choice D reason: A bacterial bone infection describes osteomyelitis, not osteoporosis. Osteomyelitis involves localized bone inflammation and destruction due to pathogens, not a systemic imbalance of bone remodeling. Osteoporosis is a metabolic condition, not an infectious one, making this choice incorrect for the described pathophysiology.