bluebird How to pass argument to promise chain?

Question

UserService.register = function(email, password, nickname, birth, sex){

    promise.resolve(email).then(getUser).then(checkUserRepeat);

    function getUser(email){
        return userModel.findUser(email);
    }

    function checkUserRepeat(user){
        if(user == null)
             return userModel.insertUser() =>HERE I WANT ARGUMENT email,password, nickname, birth, sex
            .then(insertResult);
        else
            return codeConfig.REGISTER_EMAIL_REPEAT;
    }

    function insertResult(result){
        if (result != null)
            return codeConfig.REGISTER_SUCCESS;
        else
            return codeConfig.REGISTER_SQL_ERROR;
    }
}

"userModel.insertUser" must pass argument email,password, nickname, birth, sex,how to do it?