Ans. b. Siuin Siuins have been implicated in influencing a wide range of cellular processes like aging, transcription, apoptosis, inflammation and stress resistance, as well as energy efficiency and aleness during low-calorie situations. Siuins can also control circadian clocks and mitochondrial biogenesis. `Circulating levels of natriuretic peptides are useful adjunctive tools in the diagnosis of patients with HE Both B-type natriuretic peptide (BNP) and N-terminal pro-BNP, which are released from the failing hea, are relatively sensitive markers for the presence of HF with depressed EF,. they also are elevated in HF patients with a preserved EF, albeit to a lesser degree. However, it is hi )ant to recognize that natriuretic peptide levels increase with age and renal impairment, are more elevated in women, and can be elevated in right HF from any cause. Levels can be falsely low in obese patients and may normalize in some patients after appropriate treatment. Other biomarkers, such as troponin T and I, C-reactive protein, TNF receptors, and uric acid, may be elevated in HF and provide impoant prognostic information. Serial measurements of one or more biomarkers ultimately may help guide therapy in HF, but they are not currently recommended for this purpose.' Biomarkers in Hea Failure Circulating levels of natriuretic peptides are useful adjunctive tools in the diagnosis of patients with HF Both B-type natriuretic peptide (BNP) and N-terminal pro-BNP, which are released from the failing hea, are relatively sensitive markers for the presence of HF with depressed EF; they also are elevated in HF patients with a preserved EF, albeit to a lesser degreeQ However it is impoant to recognize that natriuretic peptide levels increase with age and renal impairment are more in women, and can be elevated in right HF from any cause. Levels can be falsely low in obese patients and may normalize in some patients after appropriate treatment Other biomarkers, such as troponin T and I, C-reactive protein, TNF receptors, and uric acid, may be elevated in HF and provide impoant prognostic informationQ.