Do optimal ADMA and an undetectable urine albumin-to-creatinine ratio point to preserved endothelial function?

At age 52, these two markers provide complementary—though indirect—information about endothelial nitric-oxide biology and renal albumin handling. Both parts of the claim are supported with moderate confidence, but neither result alone establishes global vascular health.

Nitric oxide and endothelial function

• Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase. Higher ADMA can restrict L-arginine–dependent endothelial NO production; impaired DDAH metabolism, reduced renal clearance, oxidative stress, and eNOS uncoupling can further contribute to higher ADMA and reduced bioavailable NO.
• Thus, a non-elevated or “optimal” ADMA is directionally consistent with preserved NO signaling and endothelial-dependent vasodilation. In 2,096 healthy young adults, higher plasma ADMA was independently associated with lower brachial flow-mediated dilation, an NO-mediated endothelial-function measure.
• This is a biologically credible association, not an individual causal threshold: no universally validated ADMA range defines “optimal,” and kidney function, inflammation, oxidative stress, and L-arginine availability influence both ADMA and NO biology.

Urinary albumin and microvascular leakage

• An undetectable urinary albumin-to-creatinine ratio (uACR) supports absence of clinically measurable albuminuria at the time tested. uACR values <30 mg/g are classified as normal-to-mildly increased; 30–300 mg/g indicates moderately increased albuminuria.
• This argues against urinary albumin leakage sufficient to be detected by that assay, but “undetectable” means below its detection/quantification limit—not zero albumin. Proximal-tubular uptake and metabolism can also mask increased glomerular albumin passage.
• A low uACR cannot exclude renal permeability changes below the assay threshold or microvascular injury outside the kidney; repeat first-morning samples improve interpretation when suspicion persists.

Bottom line

• Non-elevated ADMA and undetectable uACR are reassuring, directionally consistent markers of preserved NO-related endothelial function and no measurable renal albumin leakage, respectively, but they do not prove intact systemic microvascular health or absence of subclinical disease.