<prompt> Glomerular filtration rate stas declining at what age?10-15 years30-40 years45-55 years55-65 years  <response>: Glomerular filtration rate GFR is the volume of fluid filtered from the renal kidney glomerular capillaries into the Bowman;s capsule per unit time.The normal range of GFR, adjusted for body surface area, is 100-130 mlmin1.73m2 in men and women. In children, GFRmeasured by inulin clearance is 110 mlmin1.73m2 until 2 years of age in both sexes, and then it progressively decreases. After age 40, GFR decreases progressively with age, by about 0.4 - 1.2 mLmin per yearRef: Ganong;s review of medical physiology; 24th edition; page no; 679 