The invention relates to methods for diagnosing bone disorders and/or cardiovascular disorders in a subject, by contacting a biological sample from the subject with (a) a nucleic acid molecule which hybridizes to miR-31 or its 5 or 3′ isoforms or variants, or (b) an agent that binds to miR-31 or its 5′ or 3′ isoforms or variants; detecting and evaluating the hybridization signal of the nucleic acid molecule or agent with a polynucleotide or said miR-31 or its 5′ or 3′ isoforms or variants; and comparing the detected and evaluated hybridization or binding signal with that of a control sample, wherein a stronger hybridization signal or a stronger binding signal in the sample of the subject compared to that of the control sample is indicative for a risk of developing or having a bone disorder and/or cardiovascular disorder.