Method for lowering plasma lipid levels or blood pressure

A method for lowering plasma lipid levels in hyperlipidemic patients for the treatment of atherosclerotic disease comprising administering to a patient in need of same an effective amount of a phenol substituted gem-diphosphonate derivative of formula (I) ##STR35## where Z.sup.1, Z.sup.2, Z.sup.3 and Z.sup.4 indentical or different are

• OR where R is H, or a straight or branched alkyl group comprising from 1 to 4 carbon atoms,
• or where Z.sup.1 with Z.sup.2 or Z.sup.3 with Z.sup.4 may form an alkylidenedioxy ring comprising from 3 to 5 carbon atoms,
• X.sup.1, X.sup.2 identical or different, are a straight or branched alkyl group from 1 to 4 carbon atoms,
• A is S, (CH.sub.2), or (CH.dbd.CH).sub.k --CH.dbd. where n is an integer from 1 to 3, and k is zero or 1,
• B is H, or an alkyl group from 1 to 2 carbon atoms,
• t is zero or 1, with the proviso that t is zero only when A is (CH.dbd.CH).sub.k --CH.dbd. were k is as described above, said amount being effective to lower plasma lipid levels in said patient.